MB 240D, 1979     The Grand Experiment (a.k.a. Albatross)

'79 240D

For Sale Sold!

On the mailing list this car in Mosier, Oregon had been discussed, with much interest in a cheap diesel. I decided that perhaps, if the car was suitable, I could acquire it for fixing up and resale. (To help defray the expenses of unemployment.) I have no personal interest in owning it otherwise, my wife's skepticism notwithstanding. There is absolutely no way this would be a practical venture were it not for all the information I've already learned about these cars, the presence of the mailing list for help and guidance, and the availability of a U-Pull junkyard from which to salvage parts cheaply. I will freely admit that this is an experiment. If it works out I might do more of these. But it's also very easy to screw yourself this way, and eliminate any profits by guessing wrong just once in the procurement phase. And it's a lot of work, often for less than minimum wage and usually by a considerable amount. Like I said, The Grand Experiment.


(√-ed items have been addressed)



Time is in hours, and cost should be obvious. I'll use U-Pull prices for used parts that I've already got. It's where most of 'em came from anyway!




Car 500
Acquisition 12 100
Glow Plug diagnosis and wiring refurbishment 2
Valve adjustment (7 tight) 2
Replaced injector return line 0.5 10
Cleaned fuel filters and replaced associated fuel lines 1 4
Tested intake and exhaust for restrictions 1
Adjusted throttle and transmission linkages 1
Refurbished RR brake 2
U-Pull shopping trip #1 3 50
Installed cleaned door switches 0.5
Installed vent knob, mirror, drain 0.25
Refurbished RF brake 2 3.5
Replaced RF wheel hub, bearings, & rotor 2 12*
Fixed driver's-side door lamp and warning buzzers (replaced diode & capacitor in warning module) 1 0.50
Fixed clock (replaced capacitors) 1 1
Fixed dash lights (cleaned rheostat) 1
Replaced heater valve, restored plumbing 1
Refurbished right headlight surround 1
Replaced left fog light 0.5 5
Fusebox refurbishment 0.5
Refurbished left headlight surround 1
Replaced differential mount 1
Miscellaneous exterior cosmetics 2
U-Pull shopping trip #2 3 20
Test-drive fuel 20
Refurbished vacuum shutoff (ignition) valve 1
HVAC panel lights 2 5
Lubed idle adjust cable 1
Miscellaneous dash cosmetics (cleaning, paint, steering wheel) 1
Vacuum leak diagnosis 1
Refurbished central locking, cured vacuum leaks 6
Replaced horns 0.5
Refurbished glow plug relay 4 1
Test-drive fuel 10
Cleaned fuel level sender, fixed Low lamp 1 1
Worked on glove box latch. Better, not great. 2
Cleaned up passenger seat tracks, made new handle 3
Put biocide in the tank (new fuel filter ready). 8
Cupholder 2
Refurbished cruise control amplifier 2
Refurbished driver's seat 5 60
Spare tire & trunk cleanup 0.5 11
U-Pull shopping trip #3 1 20
Repaired windshield washer system 2
Installed Becker & power socket 1 15
Fender dents pushed out 0.5 100
Replaced differential lube 1 5
Filled rock pit in windshield 4
Worked on radio antenna 0.5
Replaced window seal 1
Replaced missing window glide 0.25
Replaced differential 7 30
Installed underdash panels 1
Filled washer reservoir 1
Replaced missing LR lower molding 0.5 1
Replaced missing hubcaps
Replaced missing fender molding 4 31
Made lug wrench 1.50
Connected idle adjust cable 1
Fixed cruise control vacuum system 4
Cleaned and lubricated sunroof 4
Refurbished sunroof headliner 1
Washed driver's-side carpet 1
Washed passenger's-side carpet 0.5
Car wash and touch-up paint 3
Washed rear carpets 1
Detailed car 3
Waxed car 2
New gasket for primer pump 0.5
More new (used) door checks (3) 2 12
Replaced driver's windlace and passenger kick panel 1 2
Replaced hood ornament 1
Lubed speedometer cable 1
Added lamp-test to low-fuel light 1
Compression test 1
Fuel (delivery) 60




120 Hours $1106.50

$2500 – $1106.50

120 hr
= $11.61/hr


This car took 2–3× the time for repairs and TLC than I had thought, though the monetary outlay was fine. And it's a big PITA. Fun at first, but it gets old fast... There is no way this can be considered profitable enough to take the place of a regular job, even with a guaranteed stream of such cars coming in and guaranteed buyers for the results. I do not think I'll be repeating the exercise. Maybe if it's something I want to fix and drive myself for awhile and then turn over, but not on these terms. The car took far too long to sell once it was ready, this was very worrying and tied up my limited capital for much too long. My wife was also not sympathetic to having yet another car in our driveway.

Log of activity:

Tuesday, February 28, 2006

Called owner. He states that the car runs and drives, but the transmission slips in higher gears, on hills anyway. Not noticeably rusty. Manual HVAC and windows. AC compressor missing. The driver's seat is broken, driver's carpet a bit chewed. Paint can shine up, at least a bit, but there is some crazing. Ding in the passenger-side fender, enough to dislodge (and thus lose) the molding strip. Glass good. Has aftermarket auxiliary fuel tank in trunk. More than 300 kmi on it, started life in California. Price firm at $500. I made an appointment to look at it tomorrow afternoon. Will bring trailer (though the car does drive [on flat terrain]) because I'm going alone. Owner also recommends trailer.

Having butted heads with the State before, I'm taking a copy of the Washington Declaration of Buyer and Seller Regarding Value of Used Vehicle Sold (Dept. of Revenue) form to fill out. I do not want to be taxed as if it sold for high Blue Book value! According to the DMV trolls, a Bill of Sale is not good enough to establish the taxable value. As it's an out-of-State car I'm also going to be on the hook for an additional inspection fee. Will just have to pass it along! Note to self: Keep careful track of all time and expenses on this one.

Wednesday, March 1, 2006

I'm back, and I bought the car. It's late and I'm tired, but basically it looks OK for the price, no rust that I could see. Whatever is wrong with its go-ness isn't a slipping tranny so far as I could tell. I can state that the throttle linkage is all crapped up, and from the feel of it there's only partial application of the throttle. Shift points are very weird, the tranny is heavily into kickdown-ness at all times. That is not to say that there definitely isn't tranny trouble too, there's an odd groaning whine that reminds me of an old school bus, it could be that the TC also isn't happy. (I had that on my wife's SL.) Or maybe it's just bad mounts somewhere letting a normal noise pass to the body. The car moved well in 1 and R, and hopped up on the trailer with no trouble. But as soon as the car upshifts it completely loses power and starts bogging down. It's definitely the car's most serious problem, and its most immediate need. Almost everything else wrong with it is just the usual need for TLC due to neglect over the years. The PO did change the transmission fluid and filter, but that did not cure the car's problem. The quote he got for a new transmission is the main thing that prompted him to get out from under this car. The brakes drag seriously enough that there is no way the car could be driven far, even at low speeds. Not enough, however, to explain its inability to move.

I spent almost exactly $100 in fuel for the truck. We won't count the $44 for the new license for the car trailer, or the nearly $50 to fill up the truck on the way out. (Those were both pending expenses anyway.) Truck got 20.4 MPG going down, and 15.3 coming back, both at about 58 MPH. I'm surprised at the 15, that's camper territory and the car on a trailer should have had a much lower wind profile. Perhaps that cheap fuel I got in The Dalles was made from rat squeezings?

Thursday, March 2, 2006

Nothing looks wrong with the throttle linkage, other than the obviously disconnected accessories. But it sure doesn't feel right, and sure doesn't act right. The red "Stop" label is gone too.

The accessory vacuum hosing is a mess, as one would imagine. The ADA is hooked to the central locking, etc. I think the only thing actually hooked to vacuum (besides the brakes) is the key shutoff. Central locking and the AC flaps are not.

Put car on charger. Didn't take any charge, so that implies that the charging system was working yesterday. Tried to start the car, and even after three glows didn't get more than the occasional puking fire attempt. Lots of white vaporized fuel around, smelly. Bad glow plugs? Tight valves? Will look into it. The missing condensor, AC hoses, and fan may be harvested from Smelly, the woods car. Smelly (300D) also has a transmission, if it should turn out that way. Back on the charger during breakfast, I brought in the glovebox receipts to paw over during same.

Nothing too interesting in the receipts. A typical fillup was perhaps 30–37 gallons. The car did sell for $1500 a few years ago.

I checked the glow plugs after breakfast, and while they were getting power one of them (#3) was dropping 2.8 V (vs approximately 1 V rated) and the one upstream (#4) was only dropping 0.8 V, so something was amiss there. I pulled the wiring off of them and cleaned it, but #3 still had measurable resistance. (It shouldn't.) I pulled it out and found that its connection collar for the block-side connection was rusty, so I pulled it apart and cleaned it too. Putting it all back together I found that it was better, but then another one spazzed out some. I ended up pulling three plugs to clean connections before I got the system dropping about 1 V on each plug. Lots of smoke boiled off of the toaster racks that had gotten all oily from handling.

Next I adjusted the valves. Seven of eight were very tight, including all the intake valves. I tried to check the chain stretch, and if I did it right it's greater than 20°, but that sounds wrong.

While putting the valve cover back I cleaned and lubed the throttle linkages in the area. Examination showed that it was unable to push the mechanism against the full-load stop due to the link to the transmission bottoming out. A careful look showed a mark in the adjustment slot where the bolt head used to be, so I moved it there and tightened it back down. That let the whole linkage move much better.

During the valve adjustment I managed to break one of the brittle injector return lines (an extremely common occurrence), so I replaced it all with new line.

Ready to start. I gave it one glow cycle and it fired right up, unlike this morning's pukefest. It died pretty soon after that, but the second time it stayed running. Of note is that the engine is so gutless right now that it can't even seem rev to redline when cold. I then backed it off the trailer and took it for a short test drive up the hill. The automatic transmission engages in gears, both forward and backward, quickly.

Gutless. The shift linkage correction made the pedal and shifting behavior more in line with what you'd expect, but the engine has no power. Fuel filters? It drove OK, the wipers worked normally in the rain, and the heater fan did its job (though the control for it is stiff). The engine warmed up quickly and heat was good. I noticed no flaring or slipping of the transmission, but if it weren't for "L" the car never would have made it up the hill.

After lunch I dumped out the fuel filters and blew through them, they passed air freely. I blew into the feed line back to the tank with compressed air, so that should have cleared (if only temporarily) the tank screen. While I was there I replaced the cracking fuel lines that go to the in-line filter. The driveway and I are now covered in fuel.

I checked the vacuum shutoff valve and it doesn't seem to leak. Sucking on it directly shuts off the engine. There is no vacuum on the valve when the key is on. A test drive after all of this was no different. Gutless. It takes well over a second to rev up to redline with no load. Injection pump? That would not be nice. It has been suggested that a clogged exhaust (or intake), a stuck-open EGR valve, bad pump timing, or an air leak at the primer pump could cause this. Three of the five ought to be easy to verify. It has also been suggested that 20° of chain stretch could do it, and I suppose it is possible that the pump timing is off even more than that if somebody has been messing around. I think one tooth on the cam gear is worth 18°, so it is possible that the chain is installed wrong and there is only 2° of stretch. (That would actually be preferable, as then I don't need a new chain.) I need to find a way to test the quality of this chain that doesn't depend on inferred chain stretch.

So I called the PO. He said that he sold the car to me for about what he was into it for. It was not running when he got it, and he removed the clogged-up Racor filter and flushed out the fuel tank. Then it would start, but wouldn't shut off. So he bypassed the vacuum system. (No mysteries here, yet.) The people he got it from had received the car in lieu of money they were owed, so it probably didn't run then. That owner was some girl described as a bit of a 'flake', and there were three-year-old plates on the car at the time. So, lost in the misty past is what could have happened to the car, but it is not out of the realm of possibility that the 'flake' utilized a bozo mechanic who turned a running car into a white elephant. My white elephant, now!

Friday, March 3, 2006

Checked state of battery charge after sitting overnight. Didn't take any charge to speak of, so there doesn't seem to be any battery-killer active right now.

Removed air cleaner and disconnected the exhaust pipe so as to test for restrictions. (There is no EGR valve.) No difference, didn't really think there would be but one must be thorough before diving into the engine.

It was a bit below freezing and the car was very frosty. It had some trouble starting, but eventually did make it. The rear window defroster grid works, except for one wire. Good.

I pulled the valve cover again to have a closer look at the chain. It looks good, no sign of butchery. I repeated the stretch measurement, and done properly, using the timing marker rather than the RPM sensor bracket, I get about 6° of stretch. What a maroon! Can't blame the problem on grotesque timing errors.

I was looking at the throttle linkage again, and while it does contact the full-throttle stop, that stop looked suspiciously prominent. So I went over to the 300CD for a look. Though it has a turbo engine, and five cylinders, it's pretty substantially the same in the area, and its full-throttle stop was nearly 1/2 inch more screwed in to the pump than the Experiment's. So I grabbed the wrench and gave it thirty lashes (counting, so that I could put it back if necessary) until it looked about the same as the CD's. I then mashed the throttle down using the PO's idle-setting stick against the steering wheel (but on full mash). I then adjusted the throttle and transmission linkages to get full travel again, since it was able to move farther now.

Then I went for another drive. Transformation! While it's still gutless it now acts a lot more like a normal car, can get up to speed on the flats, and can even accelerate up the hill in second gear as well as first. When looking for trouble, and somebody's been messing with the car, be sure to check everything, even the stuff nobody should be messing with, and don't forget the simple stuff. I think there is some flaring now that there are a few horsepower applied to the front of the tranny, but it's much too soon to really tell. I think I need to address the dragging brakes next.

I believe the TC to be all right in the tranny because when wrapped out and shifting from 1 to 2 there is a substantial forward surge as the tranny bites into the next gear. (That's the TC doing its magic as it eats the excess rotational energy.)

...Out shopping I dropped by the U-Pull, and it may be that there are three 123's in the yard. Or maybe just one. It was closing and I couldn't go look. The posted listing was from February 19, and Volvo also made 240D's. (Stupid yard refuses to post make, just model.) But there's a 300D listed, so there ought to be at least one to look at. Will go again tomorrow.

Saturday, March 4, 2006

I jacked up the car to have a look at the brakes. The RR one was definitely badly stuck. I loosened the bleed screw and it didn't release, so it wasn't a swelled hose. I got the caliper pried off the car and found that the pucks were very sticky, a bit rusty. I drove the pucks out (serially) using a C clamp and the brake pedal, then I cleaned each bore and puck with wet and dry 600 grit sandpaper, sluiced out that side (there was a fair bit of grunge in the caliper) using brake cleaner, lubed the puck with brake fluid and re-installed the puck, which slipped in easily once it was cleaned up. The rubber boots were still intact, and were no problem to reuse. In essence this was a brake caliper rebuild, except that I didn't use new rubber. The old seemed fine, the problem was just rust buildup from having sat so long. There was a bit of a ridge on the outside edge of the brake disc, preventing easy removal of the pads, so I put the car in gear and then took a grinder to it to lathe off the ridges. The pads themselves looked like they might be nearly new, they were very thick. After putting it back together I bled that brake and then took a test drive. Much better, you could tell when coasting downhill that there was much less drag. No heat on the hub either when I got back. Progress! Definitely having vacuum shutoff problems, something is still leaking. I think it might be the ignition switch valve.

I then went to the U-Pull and liberated a basket-load of parts for the car:

Unfortunately what I specifically went there to get, side molding, was gone (as was one of the 240D's). I also procured a few spares and such for other cars.

When I got home I installed the mirror, vent knob, and door switch, then broke for lunch.

After lunch I put away the booty, and then installed the air plenum drain hose. Next I opened and cleaned both front door switches. (Though the driver's-side switches [both] don't currently work. The front switch is good, so something else is up. Probably the warning module or something like that. Both passenger-side switches work.)

Next I jacked up the car again and removed the RF caliper. It is also dragging, but nothing like the RR one was. One of the pad wear sensors is missing, but the pads are good. Spinning the wheel hub definitely makes more bearing noise than it should, it sounds 'dry'. I removed the hub and the grease is clean (new?) on the outer bearing, but very dirty looking on the inner. I had to use a puller to get it to release from the spindle. I'll probably just swap hubs from one of the parts cars. The cable for the pad sensors is starting to fall apart, so I Shoe-Gooed over the place where the sheath is missing.

Sunday, March 5, 2006

Only one of the RF brake's pucks was sticky, so I only removed and cleaned it. I went to the parts car in the woods and removed its RF hub and swapped it for the bad one. Bleeding the brake after this job was a pain for some reason. The 'new' rotor was rusty, but it polished right off with braking. (Switching rotors was possible, but it's a real pain and the rusty one was actually in better shape.) The test drive showed the odd noise to be gone, so it was the wheel bearing. As of now this car appears to be ready to drive. Long ways to go, though.

Odd fact: the threads on a grease gun mate with those on a brake caliper. Need a way to safely remove the pucks from a sticky caliper? Get a cheap hand-pump greaser and put brake fluid in it. Use a C clamp to hold in the puck you're not working on.

After church I bought a rattle-can of paint for use as touch-up. Looks pretty close, it will at least protect the bare metal along the side scrape. I plan to spray it into a cup and use a paintbrush to dab it on from there.

The warning module is by the parking brake pedal, and has a 12-pin connector. It controls the dome lamp (partially) and contains the warning buzzer. There is a diode inside that, if blown, will prevent the driver's door from lighting the lamp. This diode was dead, probably due to somebody shorting out the light bulb while the door was open. I raided the junkbox to find a diode that would work. (I kept finding Zener diodes!) Banging the module on a table restored the buzzer to operation. Sticky! The dome light now comes on with the door, and the door-open warnings (light and key) now work. The big Frako electrolytic capacitor inside was shot, so I replaced it. Now the seat belt light and buzzer works too. (Is that an improvement?)

Since I was in the area I pulled the instrument cluster and removed the clock. Both capacitors were dead, so I grabbed two spares from the junkbox and put them in. (220 µF instead of 100, but that's not critical in this sort of design. So long as it's large enough.) The clock started working again. I also reglued the coming-loose faceplate of the instrument cluster, I once cracked a loose one in half while pulling out the cluster. That was unfortunate, and not an experience I'd wish to repeat!

Monday, March 6, 2006

Cleaned the corrosion out of the dash light dimmer to restore the instrument lights. That took awhile. Then I installed the correct heater valve, and restored the plumbing to what it should be. This netted me another 3×3/8" socket wrench extension, as I found one plugging the passenger-side heater core hose. (The GM valve that was hanging there had only one output port.)

I took a look at the throttle linkage again, and compared it to a photograph of what it should look like. Weird. I'm missing a short ball-socket link, so I'll have to come up with one of these. Might have to make it out of a longer one, but that's no problem. I just need to get a donor.

I pulled one of the headlight surrounds and cut a piece of tin can to serve as backing behind the missing chunk. Then I mixed up some Bondo and filled in the profile, then set it aside to dry. We'll see if this works, the plan is to fill the holes and paint them a uniform silver gray, something approximating the color of their interior louvers. They're so full of grunge that this has got to look better.

Popped out the back seat bottom and put the dog bed in, then took the dog to the vet. That went well, so I took the car to band later. Complication: Ran out of fuel on the way! (Gauge was not reading empty.) Rolled to the side of the road near home and checked the hand pump. Dry, but then it started slurping a bit of fuel. Got the car started and ran back home where I had a couple of gallons in a can. Good thing my wife wasn't along! The emergency flashers worked well. It was dark, and the headlights are aimed poorly. Started dialing them in. The heater knobs are lit, but the row of switches is not. Probably the fiber-optic source bulb is out.

I wonder if the way the two tanks are plumbed together makes the car more sensitive to running out of fuel when the tank is low? I'm sure the fuel return 'basket' of the original tank is not as effective when there are two tanks to draw from, I doubt very much that the auxiliary tank is as elaborate.

There is sure a lot of intermittent differential noise. Got to tend to that, sure sounds like mount troubles.

The car doesn't always shut off promptly, but often will if you pull the key and thus lock the steering column. Definitely sounds like a problematic vacuum shutoff valve.

The (old) Bondo is sure taking a long time to cure!

Tuesday, March 7, 2006

I am told that this car is supposed to start out in second gear unless you are in L or have activated the kickdown. I can't imagine why! It's not like there's an excess of horsepower. It doesn't appear that the kickdown solenoid is working.

Went through the fuse box cleaning contacts, etc. Fuses all look good, I put in some spares. Can now hear kickdown solenoid click, and the reverse lights are working. Wasn't sure either was working last night, and they share a fuse (along with the horn, which does not work).

Filed and sanded the Bondo on the headlight surround. Looks good, so I painted it. Better than it was, so I cleaned off the other one and put wood chunks down in its (smaller) hole to serve as backing, then mixed up some more Bondo and puttied it too.

I replaced the one badly-ruined fog light with one from Smelly, and cleaned up both of them. Both are good, and work with the switch.

The lefthand up/down headlight adjuster wasn't working well so I removed it and cleaned it up. I think it'll dial in better now.

I replaced the one bad license plate lamp and cleaned the last door switch, then broke for breakfast.

Finished the Bondo and paint job on the other headlight surround. Replaced differential mount with a better one and cleaned out the auxiliary tank vent hose while I was under there. Adjusted hood stops. Glued torn left-side door weatherstrips. Brushed the rust off of one of the wiper arms and painted it black. Cleaned out wiper drains.

On the test drive the differential was still kind of noisy, but not as bad as it was. The kickdown switch is working, the car is much easier to drive that way. The horns do not work.

Then I went to the U-Pull and got:

(Plus some stuff on spec., not for this car.) Didn't find any Becker connectors. Stopped and put $10 worth of fuel in it.

Wednesday, March 8, 2006

I removed the right-hand wiper in order to move it one tooth on its shaft. The nut's cap was broken, so it's gluing up. We'll see if that helps its appearance.

The junkyard car supplied (how kind!) caps for the brake bleed screws.

I then pulled the instrument cluster and the steering wheel. The wheel got replaced with one from a slightly newer car. It doesn't have the ribbed horn pad but otherwise looks pretty similar, and though it had the bolt attachment rather than the nut it seemed to attach OK with the nut. Getting it back together was surprisingly painful, I think the horn pad is a bit stiffer than others I've played with.

With the cluster out I was able to remove and lubricate the idle cable, which now moves acceptably. (Put vacuum on the engine end and dip the other into ATF, gearbox and all.) There will be plenty more to do at the engine end when the time comes to hook it up.

I removed the vacuum shutoff valve and found it popped open and oily, so I cleaned it and the lines out with brake cleaner. When reassembled it stayed together and no longer seemed to leak, so we'll try it instead of replacing it. The O-ring inside looked undamaged. While there is oil in some of the vacuum lines, there appears to be none at either potential source, so whatever caused it has probably already been fixed.

The lock's security collar was all chipped and rusty, so I cleaned it up and painted it. While it was out I replaced the missing chrome trim ring.

Five of the eight HVAC panel lights were dead, so I replaced them. Some are not easy to access! While I had it apart I glued the crack in the switch bezel.

While sitting in the car doing this interior work I tried the nasty JSL aftermarket radio/8-track that's hiding down in the hole. It works! No knobs... And whatever connector used to go to the Becker is gone. I'm not sure what I should do here. I can put my spare Becker in, but the next owner might not consider that a plus and then I'm out my spare for no good effect.

With the vacuum shutoff valve no longer leaking I hooked up the rest of the vacuum system. No dice, there are obviously problems in there. No real surprise, that.

Out shopping I picked up some light bulbs to finish the job, and while I was at it I did a gross test of the 0–60 time. (One-one thousand, two-one thousand...) Roughly 25 seconds, which is in the ballpark for these. Having putted around on errands in this thing I must say that except for the sluggish acceleration it's a fairly pleasant little ride. Cold-blooded starting, though. Shutdowns were uneventful, the shutoff valve repair seems to have worked.

Thursday, March 9, 2006

Brrrr. Arctic weather again! Had to use the heat gun to thaw the door enough to open. Before I got too cold I managed to fabricate the missing link for the throttle junk, so now the cruise can be hooked up again. (I'm sure the amplifier is broken, but it'll get its turn.) I also got the chewed-up idle cable threaded back through its adjuster, but still need to come up with an attachment to the linkage.

I jacked up the corner and put in the missing brake pad wear sensor, courtesy of the U-Pull.

I got out the MityVac and checked the various (five) vacuum systems for leakage. It appears that the only real leak is the door lock system (which was expected), so that's good. There might be a slow leak in the vacuum tank, it's hard to tell. My fingers got frozen so I came in for breakfast and to put my feet up by the fire. I knew I had to open up the driver's door anyway, so I'll start chasing the vacuum system there next.

I then replaced the broken door check strap and the broken door release handle. Then I made up a new moisture barrier, and started chasing the vacuum lock system. The left side of the car is OK. I'm working through the tees that are under the floor mats, and I'm labeling the vacuum lines as I figure out what they are. I have a sneaking suspicion that the trunk-located stuff is at fault, and the auxiliary fuel tank is definitely in the way. Must it be removed to get at the vacuum tank and the fuel filler lock?

Both right-side door lock actuators leak, as does the trunk. I pulled the trunk actuator and found that what is leaking is the little collar around the shaft, the body is sealed from the elements and the main diaphragm is thus well-protected from mechanical damage and oxidation. It does not leak. I'm trying an experiment where I use weatherstrip cement (the good stuff: 3M) to coat the collar, sealing the tiny cracks with flexible rubber.

...The sealing seems to have worked, the pod now holds vacuum. I next moved on to the fuel door lock and removed it (painful!), it looked OK but leaked somehow, so I disassembled it and sealed its diaphragm too. It was rather difficult to get back in. The thing leaked down several times, but I kept pulling it out and looking at it, it looked fine and didn't leak on the MityVac, yet when in place it leaked. The lines, right? Wrong, I capped those and they didn't leak then, yet the entire assembly did. I think the tees are getting stiff, I finally got it wedged together nice and tight where it did not leak, and called it good. I will keep an eye on it.

The front passenger door lock also leaked, so I opened up the door and removed the element. It looked really grungy, so I supposed its diaphragms were torn. I disassembled the element and tubbed it, scrubbing with a bristle brush. Everything cleaned up nicely, so nicely that I couldn't see anything wrong with any of the four diaphragms. No cracks, nothing, the rubber was even still pretty 'live'. A mystery, I put it back together (all clean and warm) and it sealed. Same problem with the lines leaking, though, when it was in place. I tugged on the lines through the door hinge trying to make it worse, theorizing that there was a crack there, but then it stopped leaking altogether and I was unable to get it to leak thereafter. It's a bit of a mystery, but I think that the rubber is actually in pretty good shape (except for the one smoking gun in the trunk) and was just stiff and dirty from disuse so that it didn't quite seal in lots of places, especially the tees. Manhandling them seems to shape them up. Certainly they don't seem like they need to be replaced, I've seen lots of dead ones and these aren't.

I put the system back together and it worked great! Even the vacuum reservoir seems to be holding. The 'leak' in the RR door disappeared, it may have been spurious (I'm having a lot of trouble with the MityVac's own release valve leaking.) Whether this system will hold vacuum for more than a few hours, though, remains to be seen. Still, it's a vast step up.

I made up a new moisture barrier for the passenger door and reassembled it. (A butterflied water softener salt bag is just about the right size, though a bit thick.) I still have to reassemble the driver's door and put back the floor channels.

I then went under the hood and cleaned up the vacuum piping, including sluicing more oil out of the HVAC lines, then put it in its proper configuration. The MityVac shows no leaking of any of the vacuum consumers, except the key (brown) line when the key is off. (No leaks when it is on.) I started the car and all the vacuum stuff seemed to be working, and the car even shut off immediately with the key. Success!

Friday, March 10, 2006

Replaced the horns. For whatever reason, both old ones were dead. The vacuum tank had leaked down by morning, I don't suppose that is a surprise.

I next tackled the glow plug relay, which has been having some intermittent faults. (No light.) I opened the harness connector and squeezed the sockets together a bit (to tighten them up) and hit them with contact cleaner. I then burnished the pins on the relay and opened it up to check the capacitor values. (It's interesting that the current to the plugs is sensed via a 1-turn transformer around a reed switch.) Two of the larger caps were bad, so I replaced them. The big one (2200 µF) that runs the light was OK, oddly enough. Unfortunately while messing around on the bench I managed to slip with a probe and blew up two diodes, one a 6.8 V Zener. This took some time to find! I had a junkbox 6.2 V Zener, I call that close enough. Anyway, after several hours of circuit tracing and head scratching I got it back to where it was before I killed it. (We won't be 'billing' for that time!) The beauty of electronics from this age is that there are rarely special parts inside, component-level repair is entirely possible.

Next, check the timing. I want to try to extend it to the long side to make up for the engine's age. It obviously needs a lot of preglow! I dug some numbers out of the MB manual:

°C°FΩSpec. (Sec.)Measured (Sec.) Modified (Sec.)
–30 –22 45–65
–20 –4 35–54
–10 14 26–46
–5 23 30 nom.
0 32 8500 20–35 27 40
20 68 12 nom.
25 77 2500 8–16 9 15
80 176 300 0–4 0.5 1

On the bench with the resistance at 8500 Ω the time was 27 seconds. The appropriate trim pot inside could make the light's time shorter, but not any longer, so I paralleled an additional 1000 µF capacitor with the 2200 µF one, which extended the light time to 40 seconds. (All that circuit tracing helped decide how best to do this.) The glow timeout is about 150 seconds.

Anyway, after all this the time was better but the light was still flakey on a test drive. (I was picking up chainsaw chains, and the central locking worked fine when I tried it.) Back on the bench it was sensitive to twisting and bending. So though I had resoldered almost everything already I had not done the heavy relay and connector pins, which are the most likely candidates as they are so big (cold). I did those and then it was no longer sensitive to flexing. Back in the car the light behaved as I'd expect. Whew!

Saturday, March 11, 2006

I removed the fuel level sender and cleaned it out. Not as nasty as some I've seen, but bad enough. After a thorough cleaning the gauge moved smoothly when I moved the float by hand. After fooling with the grounding contacts, and replacing the dash bulb, the Fuel Low light also worked. The goo inside the sender smelled nasty, sour, as does the tank. I think a shot of biocide is called for, in spite of the PO's having 'flushed the tank'.

Of interest is that the Fuel Low lamp is on, for real. 3.5 gallons doesn't go far when spread among two tanks!

I then had a fun session with the glove box latch and lid. IMHO this is rather poorly designed, in that they rarely work right and are difficult to do anything with. But I was able to get the spring hooked up, though the latch is so stiff now that it hardly matters. At least the door closes properly now, though you have to slide the latch shut manually.

I decided to do a better job on the one chipped fog light, and removed it and filled (from inside) its rock pip with clear epoxy. This let me remove the clear tape from its face. I crack-filled (Leatherique!) the one small tear in the panel by the driver's door lock handle, coloring it with the Bamboo dye I've got for the 450 SL which appears to be approximately the same color as this car's interior. I also filled in the tiny dings in the B pillar cover on the driver's side. I then reassembled the driver's door. (It's a real pain driving it without a handle to pull it closed!)

...After lunch, and some firewood harvesting (we're almost out, I hope the standing dead trees are dry enough) I took the cracked windshield washer tank inside and washed it, preparatory to gluing it. The plastic is not brittle, so glue ought to do the trick.

...After unloading the truck the tank was dry, so I ran a fat bead of Shoe Goo over the split. That ought to do it!

Sunday, March 12, 2006

I pulled the passenger seat so that I could clean the tracks and put a new side (height) adjustment handle on. Unfortunately the U-Pull seat I bought didn't have a height adjuster for the passenger, and I find when I look closely that the fore/aft adjuster handle that I had planned to graft in its place is different. Bent, vs straight. I had been going to cut the handle off the front and weld it to the side, but that bend in the plastic is a problem. Well, if you're going to weld, do it right! I went to my scrap bucket and found a length of 3/8" rod. It was chromed, and I think had been part of a tool that I found somewhere, but it was all rusty. I used the torch to bend it into a triangular shape about the same size as the missing handle. I then broke off what remained of the plastic handle and welded the triangle to the end of the metal lever in its place. A coat of rattle-can black and the thing even looks almost like it ought to (though it will be considerably more durable).

I love the smell of acetylene in the morning!

I washed the tracks out in the solvent tank, they (all four of them) were filthy. I then spray-lubed the tracks with lithium grease and reassembled the seat. No real problem (though time-consuming) except that while reinstalling the seat I snapped off the front handle! Aargh! This time, at least, I have the piece, so I used Shoe Goo to reattach it. It should be fine. The seat moves easily now.

Out shopping I bought a cup holder, an in-line fuel filter, and some diesel biocide. Time to treat the tank! I put half in each tank.

On the test drive I tried out the now-hooked-up cruise control, and it acts like most of the other broken (but intact) ones I've played with: it will accelerate when you ask it to, but cannot hold a speed. Solder!

The weather this afternoon was also quite nice, so I hit the sunroof switch. It flew open without any trouble whatsoever. Closing, however, was a different story. It binds when closing and you can hear the motor slipping the clutch in the trunk. When you let off the switch you can see the roof continue to creep forward a little bit as cable tension dissipates. Hit the switch again and it lurches forward a tiny bit and then binds. Ad infinitum. Pulling on it to help it close does nothing, so I don't suspect a loose clutch. I'm going to have to open it up and go through it. At least I've done one before.

This evening I removed the cruise control amplifier, stripped the varnish off the back, and resoldered about half of it before I ran out of time. Oddly enough, the often-bad electrolytic capacitor that is a main suspect was in great shape, so I left it in. I slipped the amplifier back into the car, and on its test drive the cruise control worked. It surged a bit, but that's main symptom #2, and probably a sign that not all solder joints are yet good. At least on this 240D a surging throttle pedal is barely noticeable due to the lack of horsepower. Progress!

Monday, March 13, 2006

I soldered the remaining portion of the cruise control amplifier, giving special attention to the circuit areas I've noted before (C18, see here) that can cause surging. (C18 had not been resoldered yesterday.) I reinstalled it (temporarily) for the next test drive.

I water-tested the glued windshield washer tank, and there is another small split in the bottom that I missed the first time. So I glued that too.

I pulled the windshield washer pump from the car and brought it inside. It was stuck, so I hit it with PB Blaster and started feeding it spoonfulls of 12 V. It eventually broke loose and blew PB at me, but thereafter seemed to behave itself. I blew through the tube in the car and it's occluded, so I've got some cleanout to do there too.

I then pulled the driver's seat. (I found 46 cents!) I got the seat tracks off and soaking in the solvent tank. This seat has been heavily messed with, bolts are missing and incorrect fasteners have been used in places. The broken springs in the seat have been bolstered with foam. (That was a good job, you can't really tell by sitting on it.) There is a lot of corrosion all over the seat belt buckle area, I think something nasty was spilled on there, that side of the console is a mess too. I'm going to try taking off the bad seat back cover to see what an upholstery shop would charge to replace the one bad panel (again). Whatever was used before was not MB-Tex. They did a good job of sewing, but the material simply didn't hold up. The seat disassembly/reassembly was also sloppily done. The sagging was caused by a missing bolt, and one of the lumbar crosspiece screws had fallen out. The armrest indexing bolt was also loose.

I called around and found an upholstery place that knew what an MB was and guessed that a new sewn-in panel might run $60–80 (using generic material), depending on a lot of factors and he'd need to see it to know better... They also estimated a very quick turnaround, unlike some places I called.

I finished disassembling the seat and liberated the cover. While I was in the area I cleaned up under the seat. Then I installed the U-Pull seat, to serve as a place to sit while the real seat is getting fixed. This newer seat is actually in poorer shape than the old one, but the armrest is not cracked so I may try to switch those.

Occam's Razor. The windshield washer nozzle system wasn't occluded, it was frozen! I tried again when it was warmer and it blows freely. I think there's a crack in one of the 90° fittings though. I blew it all out with compressed air so it won't freeze up tomorrow when I finish fixing it.

I grabbed a spare tire from the pile and put it in the car. I borrowed the lug wrench from the Frankenheap, at least until I can get one for this car. I put the trunk back in some semblance of order, and put in a real trunk light bulb in place of that ridiculous GM thing that was rolling around in the trunk and obviously never fit right. (Flat ends vs pointed.) I put on the two hubcaps that I have.

...Out shopping today I got a firm quote on fixing the seatback cover at $60. The guy'd done these before, and even thought he had some of that same fabric left over, but when he looked there was nothing. He figures he gave the remnant to the customer who had the work done. Regardless, he figures he can make it much better, even just using whatever he has that's closest. I also got a paintless dent quote for $100 to make better the scrape, at least enough that molding would fit right. I also stopped by the U-Pull and picked up some Becker radio connectors and a window channel seal. I also got two door pockets (and door panels/handles), but I don't know if I'll use them or not. And I got another 90° fitting for the windshield washer.

The cruise control generally worked, but was unable to hold a speed over 70 MPH. It may be that its linkage adjustment was too loose, so I tightened it up a bit. We'll see next time. The whine from the rear end is very annoying, that will have to be dealt with. I also gave the right headlight aim a tweak based on last night's test drive. (Nearly there! Dialing in headlights takes a fair amount of time.)

...Another test drive tonight, and the cruise is not yet right. Will probably resolder it again to see if it gets happier. About par for the course. Otherwise, with a carload of people, it behaved itself pretty well.

Tuesday, March 14, 2006

Resoldered the cruise amplifier again. I hooked up the vacuum pump again and tested the actuator, feeding it 12 V it is able to pull the throttle all the way to the stop, even with reduced vacuum (a controlled leak). So that's not a problem.

I finished installing the windshield washer system, including a new 90° fitting, and put in a little bit of blue stuff. The passenger-side squirter was not working, so I had to chase that. (The squirter was occluded, a dental pick and some compressed air took care of that.) Then I re-aimed the squirters.

I installed a Becker Europa Cassette radio, and an auxiliary power outlet. (For cell phones, etc. I find it rather awkward to use the actual lighter socket for such things.) Discovery: it's not a power antenna, it's the manual variety. Duh!

Test drive. Cruise still is not right. Wiper motor shrieks sometimes too. Got stuck in the fresh snow going home, but managed to scream up the hill on the third attempt. Great, should have stayed home!

Wednesday, March 15, 2006

In the night it came to me that the spastic cruise control symptoms are strange enough that it could be its internal power supply after all. And why did that old filter capacitor have better measurements than any new one I've ever tested? Now that I think about it I'm going to replace it. Sumpin just ain't right!

Replaced capacitor. Still tested good, but I just don't trust it! I replaced it with another capacitor, but with a 0.1 µF decoupling cap in parallel with it. Standard practice when I was a pup.

I jacked up the rear of the car again and checked the lube level in the (noisy) differential. It was full, but of a nasty black sludge. I poured in some leftover gear oil I had, I suppose I'm going to have to flush it out and replace the lube altogether. However, I don't know that I trust the differential to be still good, and I'd hate to invest the gear lube in a bad part when getting another differential is so inexpensive. ($28, not a trivial undertaking, though.) This differential, though, has external bolts for the half-shafts, and the 240D candidate in the yard does not.

Other noise candidates? It's a classic gear whine that sounds like it's coming from the back, doesn't vary on cornering, and is loudest at partial throttle settings at lower speeds. I replaced the differential mount with a less-collapsed one, one that I believe came out of our 450 SL as a case of PM. Not much of a change. Subframe mounts? Spring pads?

While taking the car to the paintless dent removal place I thought the differential was quieter than it had been. Enough that I think I'll clean it out and put in fresh oil. The cruise control, unfortunately, was the same. It works at first, then sinks about 5 MPH (to 60).

Paintless dent guy did a good job in restoring the profile of the fender. You can still see some rippling, but it looks pretty good. $100. I also picked up the seat cover, it looks great. Not MB-Tex, but the color is a good match. $60. I stopped at the liquidator's and bought a half-price windshield rock chip repair kit to fill the tiny rock pips. I stopped at the auto parts store and bought two quarts of gear oil for the noisy differential. (None left at the liquidator's.)

I'm no longer sure that the differential is any quieter than it was. Maybe I should just get that other one and put it in. It's unlikely to be bad, after all. Put the new oil in it instead?

Thursday, March 16, 2006

I surfed a bit and found an article where the guy's Jag differential had an intermittent whine and he fixed it by slightly increasing the pinion preload. Might be worth a try, I actually have the special differential castle nut socket that this car probably needs. My brother thinks that I should just replace the differential. He's probably right.

Anyway, I started putting the driver's seat back together. I welded some splints around the two broken seat bottom springs, and I used fabric glue and canvas to back up the tears that are starting in the front vertical face of the seat bottom cover. (A common malady.)

After breakfast I started reassembling the seat. Slow! I cleaned and lubricated the seat tracks. The donor seat (newer) is constructed slightly differently, so swapping the handles over is a bit more of a pain than it could be.

After lunch I finished putting the seat back together and in the car. Takes a very long time to do right. I also reassembled the donor seat, it's easier to use it as a donor next time if it's all together. I decided against swapping armrests because of the color difference, and there's also a shape difference. The old one's cracks are minor when compared to most I've seen.

Next I drained the black glop (literally!) out of the differential. I've never seen such goopy stuff. The first mound of it that fell out into the oil pan, before I got the ooze going through the drain hole to the inside, stayed there during the entire operation. It was like black runny peanut butter. I let it drain for half an hour or so, then put the plug back in and filled it with diesel. Then I ran the car in gear for a minute or two and drained it again. The diesel came out black, but the glop in the bottom was hardly touched. So I got out the oil sucker and slurped it all up. Then I repeated the diesel sluicing, and then sucked it out once more. I put in 1.5 quarts of gear oil and took it for a test drive.

Still noisy. Crap. The differential that's in there bears a 115 part number, so I'm sure that either of the differentials I have squirreled away will work. (I think I got one from a 123 and one from a 115.) The one that I put on the parts car (so it would roll) has the same bolt-based attachment for the half-shafts, so that's the one I guess I'm going to use. I think it came off of a 240D, though it is on a 300D right now. More work to liberate it first, but what are you going to do? And of course I have to install them both as well. A pure trade, 2× the work!

I soaked the radio antenna with PB Blaster and Kroil. I'm trying to get the last segment to come out, but it doesn't look good. There are four segments, right? I only get three to extend.

The day wasn't quite over, so I tackled the wind leak in the driver's window. The sealing lips in the channel were torn, so I had liberated one from the boneyard that was better. I swapped in the replacement, it actually went pretty smoothly. While I was in there I saw what the odd clunk was: the glide for the window regulator was missing so the back of the regulator arm would hit the guide channel periodically. I grabbed one from Smelly and put it in, then reassembled the door and took it for a drive. Quiet!

Friday, March 17, 2006

Raining, great. I got the parts car (Smelly) jacked up and put some little jack stands and big firewood pieces underneath it for safety. The differential came down and out a lot easier than I remember it going in. It only took an hour to get it into the bed of the truck. Breakfast time! I removed three of the red molding mounts from the parts car, and some rubber exhaust pieces and brought them up with me.

Back at it, three hours' work had both differentials loose on the tailgate of the truck. Mostly I had to follow the instructions in the manual, I lowered the entire rear subframe assembly of the car except that I left the shocks and parking brake connected. (I'm not removing the subframe, just lowering it enough to get at the mounting bolts for the differential.) The 'bad' differential still had a lot of glop in it in the crevices. Twisting its pinion by hand showed it to be very easy to move, entirely too easy and indicative of too little bearing preload. Probably due to wear, it was a lot looser than the one that's going in. I know too little preload can result in excess noise. Internally the gear teeth looked fine. I could have tried tightening the pinion nut as I have the special MB socket for the castle nut, but I didn't want to have that not work and then need to do the swap anyway. I plan on a road trip in this car tomorrow and I need it done today, I've pretty much run out of time. I imagine that the glop was an attempt by someone to quiet the differential. Methinks they would have had better luck adjusting the pinion preload instead. The glop certainly didn't seem to cure anything, the pinion preload might have.

This really is a rust-free car, every fastener came loose readily.

The swap-in went easier than the removal, partly because the FUD factor was missing. The use of a third jack, a small one, was useful for lifting and lowering the subframe in order to get various fasteners started. I put the differential in sans half-shafts, so it was a lot lighter and less awkward. I just bench-pressed it into place, it's not really that heavy. Before I did that I removed and cleaned the breather vent. I greased the centering post before I mated the differential with the driveline.

While I was there I ground off the ridge on the LR brake disc too, the ridge had impeded removal of the caliper. Brake pads looked good.

The muffler was tied up with wire and one of its bumpers was gone too. At idle sometimes you could hear it squeaking as it vibrated. Since I had to take the exhaust system loose for this job I put it back with some rubber parts from the parts car (Smelly). I still need two more donuts to make it a full complement, but the squeaking should be gone. I used the wire to hang up the brake calipers!

Two and a half hours after starting reassembly it was back together, and a half hour after that everything was cleaned up and it was time for a test drive.

Success. The whine is gone, the car drove well.

One of the holes for the red molding mounts had a bit of rust on it, so I cleaned it up and used the rattle can of paint I'd bought for touch-up. (Spray onto end of brush and dab.) It really is a very close match. After the paint had dried I installed the red mounts, preparatory to installing molding (should I find any in Seattle).

Saturday, March 18, 2006

Started thinking about the cruise control's strange operation, and it could be that it's running out of vacuum, though I've already checked the vacuum pump's pumpdown time on an empty brake booster. I checked the manual (not easy!) and found that the cruise control's actuator is supposed to share the vacuum reservoir with the locking system. Maybe that's it...

...Nah, it's plumbed correctly. I don't know what to try next. But we need the car buttoned up for the trip so I put the amplifer back where it belongs. I hope we can use it on the trip, but if not it's not the worst thing that can happen. Then I installed the under-dash covers, those sure are a pain to get back! I'll probably have to take them off again later, but we needed the (sadly compromised by the auxiliary fuel tank) trunk space. I put a rubber floor mat over the nasty patch on the driver's side. That'll dress it up a bit.

The paintless dent guy drilled some holes in the car for access (they always do), and I needed to treat and plug these to avoid mud build-up where it shouldn't go, and rust. I painted the hole in the metal (behind the turn signal), then glued a patch of pop can over the hole, then painted that. I glued some black ABS plastic over the hole in the splash guard.

I stowed the Racor under the hood where it goes, it's not mounted right (part of the bracket is missing) but it's wedged in by the washer reservoir and won't go anywhere. I also filled the washer reservoir with blue stuff, since the test fill didn't seem to leak out.

I went down to Smelly and removed the small left lower rear rocker trim molding. It just pried off, I cleaned it up and popped it on the car with a rubber mallet.

I then put some tools and work clothing in the trunk, checked the air in the tires (good), and it's ready for our trip!

Drove to Yakima. Italian tuneups on several of the larger hills, most of which resulted in reduced speeds, floored in third gear for miles. Car did well, in spite of this. No problems, fairly quiet and quite comfortable.

Sunday, March 19, 2006

Before we left Yakima I went to a neighborhood yard sale and grabbed a tire iron for 50 cents. No good! It's too big, but it's got a nice long handle and a pointy end for prying off the hubcaps. Maybe I'll weld a surplus 17mm socket to it to make what I need.

Drove to Roy. White Pass was a pretty serious Italian tuneup. No smoking going up, but going down we used a lot of engine braking and there was a fair amount of blue smoke when the throttle was pressed after coasting. This could indicate that valve stem seals are less than optimal. This, however, is not much of an issue on these cars.

Was going to get to Roy too early (nobody home) so we redirected on up to Seattle proper and visited Clay (redghost) and Gump. Talked cars for a couple of hours, wife and son played with Clay's family. Was a beautiful day to stand outside with the car hoods up. Gump is no POS, it is cleaning up nicely and ought to end up being a very nice ride. Unlike the poor Frankenheap.

Clay gave us a couple of white hubcaps and a rubber exhaust donut. The car is getting pretty complete!

Monday, March 20, 2006

Called every salvage yard I knew of in the area (Clay's list), and nobody had a 123 to pick from, except Aurora Auto Wrecking. One yard had crushed his 123 only last week. Aurora said they had my molding.

Tuesday, March 21, 2006

Drove on up to Seattle again to get the molding. Aurora is a small place, but has a lot of stuff. The 123 molding was there, as was the small spring clip for the idle cable! Both items procured for their minimum $15 yard charge. Overpriced when compared to a U-Pull, but not much money total and with the serious advantage of getting the car 'done' now. Except for the AC business (uncertain future) and some TLC. I installed the molding in Aurora's parking lot. Of course, the special trip up cost maybe $15 in fuel, so the effective price was not so hot. But the done-ness!

Wednesday, March 22, 2006

Long drive home. Italian tuneups over Tiger Mountain, Snoqualmie Pass, and the gorge at Vantage. Never dropped to less than 45 MPH, usually 50+. (The usual 70–75 on the flats, of course.)

For whatever reason (luck, and timing) we never hit any of the nasty Seattle traffic, nor had any problems going over the passes. We weren't even that much of a problem for anybody else as traffic was uncommonly light. A great trip!

Got home and the fuel light came on as we were nearing town, followed shortly by the trip odometer rolling over. Filled up at 1024 miles, and only got 23.5 MPG. Less than I would have thought, especially given how underpowered the car is, but it was working pretty hard the whole time!

I'm a bit disappointed with the car's mileage, but very happy with the car's range. Regardless, the car drove very well. We were pretty happy with it, and my wife even said "I was wrong." Now that is a real milestone! She liked the dual-zone manual HVAC's adjustability.

I'll have no qualms about selling this car to somebody, and I can prove it: I subjected my own family to a serious road trip in it, with no reservations, and no problems. After all the Italian tuneups the car is running smoother and stronger than ever before and starts easier too. (Though still a bit cranky when compared to most of our other cars.) If I needed to I would hop in this car tomorrow and drive it anywhere without hesitation. (But I would really like to get that cruise control fixed first, please. It's got an erratic surging problem still, and I no longer suspect FET damage. It can resume to the right speed for a few seconds before sinking and getting weird.)

I no longer think the motor mounts are bad, I think the idle is just set too low. Once the idle cable is hooked up right that should make this a non-problem.

Kind words from Clay:

Had a really pleasant chat with Jim when he came by to get the hubcaps. Nice family and that 240D is a SUPERB car for what it is. I must bow down to Jim's ability to take dead iron and make it come back to life. The car got all the way to Seattle from Spokane and most likely will get even better on the way back.

The super large tank in the trunk should give it an 800 mile range easy. He got paintless dent repair to the front fender and with the trim strip back on, it would be hard to tell it was hurt unless you get really close. He wants to get the AC back in and working, as well as CC to function well. If he sells over here, he can expect his base price of $2500 easy.

This is not a Kansas 220D car, but a really nice example of the W123 in #3 condition. With a good rubbing out, a detailing, spit shine to the engine compartment, I think it could be a #2. No excess smoke or noise, just a great klatta klatta. Anybody interested in a car with some upgradability should consider it for a friend or relative. List members would want to take the next step in car care and cover the cosmetic items and get a timing chain in at the next valve adjustment.

I think it has curb appeal, great example of a 10 footer, and better than many of the '79 cars I see available. Just my $0.02

Thursday, March 23, 2006

Resurrected the cruise control bench test setup. Started fiddling with the amplifier. Acts right, near as I can tell. I did resolder some parts around the relay, it seemed to be a bit sensitive to tapping in that area. The waveform to the actuator throbbed at first, but after all the handling it was stable and acted like others I've seen. We'll see on a test drive today if it's any better.

...No, it's not better. While I was out I bought ($1) a 6-point 17mm socket to weld to that tire iron I bought. That ought to make a good tire iron for hubcapped wheels. (The pointy end of the handle can pry the caps off.)

I messed with the cruise amplifier some more, even going so far as to connect a SP4T switch to several test points inside and going for a drive with a meter connected to the switch. It was still spastic, and a different amplifier I tried was worse. (I don't think it was a good one, though it is one I've tried to repair. The other two in the box were definitely NFG.) However I can say that the speed feedback signal is good. Nice and linear, with no jumping. (The output of the error amplifier and the current feedback test points are both jumpy. But not on the bench. I would think that any problem would be at the error amplifier stage.) I decided to clean up the contacts on the actuator better, and this time pried apart the connector shell. There was a spider nest inside, so I cleaned that out, scraped the pins of the actuator, squeezed the connector sockets together a bit, scrubbed them out, and put it back together. I also tied the actuator directly to the vacuum tap on the brake booster line, bypassing all other consumers.

It worked a lot better. I put the vacuum system back as it should be, and it wasn't so good, though I think it was better than before. It may be that we're running out of vacuum and that's causing weird symptoms. I'll hook up a gauge tomorrow so I can watch it during a drive. It could well be that there's more than one fault here. Those can be fun to diagnose!

After dinner I spent a few hours going over the circuit board on the bench. The output 'breathes' sometimes, but not others. I do not know if this is significant, and I found no particular mechanism for this behavior, and no particular way to induce or eliminate it. Using a signal generator as the speedometer signal should eliminate feedback that way, the only other feedback is the current sense to the actuator. All the capacitors in this circuitry seem to be connected, and good. Tacking a few extra filter caps here and there had no effect. I've forgotten what little servo theory I knew, but it could indeed be normal if it had been thought harmless by the original designers.

I have learned that the set speed, held as charge on the FET's input capacitor, is stored as a delta from approximately 60 MPH. That is, Vcc/2 is the initial output voltage of the error amplifier, and this is approximately the voltage out of the tachometer circuit at 60. So if you have a cruise control that always seeks out about 60 MPH when set it may be that the FET (a BSV81) or its capacitor is shorted, or that the K2 relay (responsible for setting the speed) is stuck on, or some such fault.

Friday, March 24, 2006

Today looked like rain, so no sunroof operation! More cruise control madness I guess.

I dug out the nasty Hella vacuum/pressure pump I'd gotten from an early 126. This is a badly-designed nightmare that is not very durable (though the motor/piston assembly inside looks very robust). I bought a broken one for parts thinking it was like the later ones, only to find it is not. Up 'til now I've had no use for it. (I did repair it once upon a time, but patching torn long-throw small-diameter diaphragms with glue is a short-term solution at best. This pump was merely held in reserve in case I ever had a car that needed it, or for reference.) It is poorly suited to converting it to a pure vacuum-only pump because of its integrated snap-action switches and valves, but I'm giving it a try. I found that if I take the cover off and close both ports thus exposed I can get it to snap itself into a state where it is sucking continuously from one of its internal vents while blowing out its normal output port. This internal vent, when plugged, doesn't result in the internal diaphragm switches snapping over, yet produces a vacuum. Good, maybe there is yet a use for this nasty POS. (The later-style pumps are easy to convert to this duty, but I don't want to lose my one spare.)

I made a collar for the vent out of a strip of pop can and super glue, into which I have Shoe-Gooed a plug with a piece of Tecalan vacuum pipe sticking out. This collar was duct-taped around the vent. I hooked a lighter plug directly to the motor, bypassing the time limit circuitry. I teed into the car at the tap for the cruise and ran a salvaged yellow vacuum line through the firewall to the passenger seat. This whole mess (along with the MityVac [for its gauge]) was teed together with a check valve to the pump so that I could read the system's vacuum level while driving, and augment it by powering up the auxiliary pump. Then I went for a drive.

Left to itself, the system vacuum stabilized (eventually) at 17" Hg. Turning on the cruise control immediately resulted in a significant drop, to around 10" Hg, with a slowly sinking average. The cruise control worked well at this point. After a bit of driving, however, the vacuum level had dropped to below 5" Hg. Once it was below 4", the cruise control stopped working well and the familiar spastic behavior resulted. This was very consistent.

The real test was plugging in the vacuum pump. Vacuum immediately rose back to 10" Hg of vacuum or thereabouts, and the cruise control resumed correct operation. Bingo! I tested on back roads at 35 MPH, and on the freeway at 70. While on the freeway my vacuum adapter blew a hole in its side because I had been impatient and hadn't waited for the glue to completely dry; with the cruise off and both pumps working in parallel the vacuum level soared to the failure point, so the testing ended early. Not so early as to compromise the conclusion, however.

So, either the vacuum pump is weak (though earlier I had decided that it was OK) or there's a restriction that's preventing adequate airflow from the actuator and reservoir. (I suppose there is a small outside chance that the actuator itself is consuming more vacuum than it should, but this is unlikely.) Next step: thorough vacuum source diagnosis!

So I looked up the spec., and when I disconnected all the auxiliary stuff and measured the vacuum rise at the tap when the engine was started after exhausting the brake booster it took about 12 seconds at idle to bring it back to 15" Hg, about 1/2 Bar. (This appears to be a 10" brake booster, so I'm assuming single diaphragm. I believe that the vacuum pump is single-diaphragm as well. These factors let you find the right line to read in the manual's chart.) That is within spec. so far as I can tell. However, with the auxiliary stuff hooked up it takes much longer than spec. to pump down the auxiliary tank. But I'm measuring in the wrong place to duplicate what the spec. calls for. I found no overt restrictions in the vacuum plumbing. I suppose that the plumbing upstream of the actuator could be too small, but is this possible? It looks factory enough.

All this cruise crap was getting old, so I welded the 17mm socket I bought to the end of the yard-sale lug wrench. That, at least, was easy! New replacement factory lug wrenches are readily available and not expensive, but they lack the chisel point that makes removing the hubcaps easy. This homebrew wrench ought to work better than factory.

Then I connected up the idle cable, now that I have the spring clip. I put a long thin brass bushing (a drilled-out rivet from an old door switch) over the frayed end of the cable, and used a collar with a setscrew and aluminum sheet metal inserts to clamp the end of the cable. The throttle linkage required a little bit of adjustment in order to get the correct range on the idle cable. (It was tight, because the frayed end was a bit short.) The dash knob now works as intended.

Saturday, March 25, 2006

Removed the test contacts in the amplifier and put it back in its case. Put together the bench vacuum pump again now that its glue has had a chance to dry. When stuffed inside its foam 'football' it's really quite quiet. It ought to come in very handy from time to time, and it's nice to finally have a use for that wretched pump I got stuck with.

Sunday, March 26, 2006

Reinstalled the cruise amplifier. Installed the auxiliary fan support brackets. No auxiliary fan, but this is the best place to store the brackets! Glued torn right-side door weatherstrip. Checked brown and green vacuum lines (again) for leaks, nothing. I don't know what to think. While driving it today it seems to me that the throttle pedal gyrations (which you can feel with your foot if you try) must be abnormal, and reflect an excessive consumption of vacuum by the actuator. But why does it do this? It doesn't on the bench.

I thought I'd better cover some bases, something I believe to be true is not. So I tried a different stalk switch. A long shot, but in theory it is possible for a contact that doesn't open-circuit all the way to disrupt the amplifier. No dice, the car drove the same. Maybe I need to swap actuators too to be sure of it.

I also started the resoldering process on the two dead amplifiers I have in the box. If I can get them to work on the bench I'll try them both in the car to see what happens.

...Got one running well on the bench and took it for a drive. Exactly the same results. Definitely pointing away from the amplifier.

The other spare amplifier, after resoldering, goes into immediate deceleration. Probing reveals a climbing FET output voltage, for no apparent cause. Looks like a leaky FET, probably gate punch-through damage induced during the resoldering resulting in leakage from the Drain. Be careful with those! FE376 is unobtainium, the BSV81 is difficult and expensive to find. It may be that a relatively available/cheap 3N138 will work as a replacement, should I ever need to fix this one.

This exercise leaves me with two spare vacuum amplifiers that seem to work, one from before and the one I just fixed. That's enough!

Monday, March 27, 2006

Removed the cruise actuator and brought it in to the bench. Seems to act exactly like the one I use for testing. No abnormal appetite for vacuum in other words.

Removed vacuum pump. What a PITA! Disassembling it I find no torn diaphragms, and the valves work. There was oil in one of the valves, the intake, but I suspect that this car had an oil leak into the vacuum system at a prior date that was not completely cleaned out. I suppose it could be that the puddled oil was preventing the valve from working fully? Let us hope. The cam and bearing are perfect. The rubber bits all look good.

Reassembling the pump looks to be even harder than disassembling it. I put the valve cover back together and sucking and blowing on the two ports results in good behavior. No backwards leaking that I can detect. The pump requires 1" of preload on the main spring for reassembly, I used a block of wood on the floor as a spacer while standing on the pump. Awkward, but do-able.

The reassembled pump went back on the engine easily enough and 'squawked' as it pumped when the engine was turned by hand. Sounded normal enough. With the engine started the brake booster pumped down in a normal amount of time. Went for a test drive.

Same. Crap. That was the last major piece to look at and it looks good.

Y'know, as I mentioned before when weird things happen that you can't explain then something you believe to be true is not, one of your basic assumptions is wrong. So I started a round of divide-and-conquer diagnosis. First I unhooked the brake booster and used duct tape to secure the vacuum check valve (which feeds the reservoir/doors/cruise systems) to its end, taped shut the usual tap for the accessories, and went for a drive. Perfect cruise operation, other than the lack of power brakes! The vacuum level never dropped much at all. The pump has got plenty of 'oomph'. I then hooked up all the vacuum taps to this point and tried again. Still good. I then taped off the brake fitting and moved the check valve to the usual tap, though bypassing the splitter and much of the hose and tried again. Better than usual, but not good. So that eliminates the brake booster as a leak (not that I suspected it but we are in full science mode now). At least this lets me hook up the power brakes again! I then removed the usual vacuum hose from the tap and used a section of 1/4" fuel line as a vacuum tap. This fits over a stepped portion of the body of the vacuum fitting, and should eliminate any chance of restrictions in the usual hosing causing problems. The check valve was taped into the other end of the fuel line. Still not good. That leaves the vacuum tap as the only remaining potential culprit. It certainly looks normal enough, just like ones in other cars. I removed the brake vacuum line from the car and heated the plastic tap fitting with a heat gun and drove a framing nail down its throat to stretch it out a bit. I couldn't get it in all the way. With it stretched a bit by the nail I then ran a drill down it to finish opening it up. Next I blew out the shavings and put it back on the car, using the fuel line tap system. I used a section of cruise actuator bleed line (extra large) as the thing to go between the fuel line and the 4-way splitter. Duct tape was used to seal it all up as an extra precaution.

Success! On a test drive the cruise worked well, and the vacuum gauge never fell very far at all. Pumpdown time on the reservoir was dramatically reduced. Either something was caught in this vacuum tap, it was defective all along, or somebody replaced this tap (or more likely the entire line) with one that was wrong for this car, perhaps one that had a built-in restrictor orifice that was too small.

As a bonus, when the car is shut off it shuts off much faster now, more like every other diesel we have. It used to take up to a second to die. Something was definitely wrong, and I wasted a lot of time chasing what turned out to be a very simple problem. I may later try restoring the normal vacuum hoses at the tap, it'll probably work just fine now.

Finally, moving on. I glued the loose passenger map pocket to the door skin. Inelegant, but should work. I was careful so that it can be removed fairly cleanly if the pocket should ever get replaced.

...On a freeway test drive today the cruise worked even better than it did at low speed, mostly because the car is less sensitive to throttle variations at higher speeds. Perfectly acceptable, if you ask me. I need to look at the throttle linkage again, it may be that we've lost a little bit of onramp power since I dinked with it while installing the idle cable.

It's a pity that other obligations prevented me from tackling the sunroof today, it was beautiful out. It's supposed to rain tomorrow.

Tuesday, March 28, 2006

Yep, raining. Adjusted the throttle linkage again to get better access to full throttle. Loosened the ADA screw two full turns. Tried a test drive, no real difference. Car doesn't smoke on heavy acceleration, and sucking and blowing on a line connected to the ADA's port didn't seem to make any difference. I whipped the full-throttle stop four more lashes of the wrench, just for grins, and drove it again. Not really any different, but I hooked up the MityVac to the ADA, and when I pumped it up to 15", floored it, and then released the vacuum I could feel a small surge as the ADA reacted. So, it's not totally dead anyway.

The weather cleared up a bit, so I dove into the sunroof. Very sticky, which I could tell once I'd unpinned the operating cable. Can't even slide it by hand, it takes two! Try that while at the same time trying to flip the switch.

Anyway, it was painfully obvious that naive attempts to lubricate the sunroof had been done. The two shiny cover rails (with the screw heads in them) that are exposed when the roof is open were caked with what looked like a bad varnish, the remains I suppose of some random lubricant caked with dirt. Of note is that this is a non-bearing surface, and needs no lubrication at all! I put these in the solvent tank while I did the real job. The roof came apart easily enough, having done it before helps. The difficult part is cleaning out the rearward part of the sliding track where it's buried behind the headliner. I used a bit of rag clamped into the end of a straightened coat hanger and dipped in solvent. Fortunately the rear part of the track seems to have escaped the home lubricator. It was fairly clean, especially when compared to the front part of the track.

With all of the crud scraped and dissolved out of there, and the same for the sliding feet on the roof panel itself, I lubricated it all with vintage Lubriplate (see this for details) and put it back together. Even after an hour in the solvent tank the rail covers needed heavy scrubbing with a rag to shine up. The roof panel slid easily enough by hand when I put it back in place, so I finished putting all the bolts in and tried it out. It still got stuck at the back, just about as bad as before! WTF?

I started taking it back apart, and with it disconnected from the cable and bracket it slid easily enough again. As it turns out, the sliding bracket to which the roof panel screws (and through which runs a tube inside of which is the cable from the motor) needs to be pulled forward out of the car as well. (Run the cable all the way back first.) The inside of this tube was all gummy and was preventing the bracket from sliding easily over the sheath of the cable back under the headliner. I cleaned it out with solvent and lubricated it too. Upon reassembly the sunroof then worked properly.

Now for the small tears in the sunroof headliner panel. I took it inside to a table and cleaned off the metal side rails where the glue had failed and the material was loose. I then used contact cement to reglue the panel to the frame. With that done I cut some small pieces of scrap headliner material I had and cemented them behind the tear and the hole that was in the panel. The scrap material was even the right color! Same hole pattern, too, which helped with the hole. It is a bit puckery still and not nearly as invisible as I'd hoped, but I still think it's better than it was. With the hole patched it should no longer draw probing little fingers... A final treatment with Simple Green to clean off the whole panel and then I installed it back in the car. A drop of oil on each metal snap clip helped ease them back into place.

Just about done, except for the detailing. (Wash, touch-up paint, wax, clean the interior.) I have had no problems with the battery the entire time, I think its only problem was difficult starting combined with not letting it charge back up. (Especially easy if you didn't get it started!) So I will consider the PO's report spurious and will mark it as taken care of.

Began the detailing process by washing the replacement driver's-side carpet in the tub. (Too cold to do it outside.) Used laundry detergent and a lot of hand scrubbing. On the plus side most of the oily car grime has come off of my hands! Took a lot of rinses (8?) to get the water coming out to be only slightly dirty and soapy. Good enough for a floormat! The process was extended by my boy's desire to 'help'. Fun, but slower. Hung it to drip-dry in the tub, will put it in front of the fire when it stops dripping.

...Moved it to a drying rack in front of the fire. Tromped it on the living room carpet a bit first, to squeeze water out of the foam backing. (The living room carpet will dry.) It looks pretty good, the older loop carpets always seem to clean up much better than the newer velour.

Hard to believe that I bought the car only one month ago today. It seems as if I've been working on it forever...

Wednesday, March 29, 2006

Carpet is still not all the way dry. The culprit, of course, is the foam underpad. This (carpets) is really a summer job but we can't wait for it!

My boy and I washed two more carpets (of the five) in the tub this morning. These are drip-drying outside as it has turned into a nice sunny day. They were, as expected, much less dirty than the driver's carpet and so took much less time to clean. They look good.

It was so nice outside I washed the car, even including cleaning out the hood drains. Then I got out the rattle-can of touch-up paint and had at it. I sprayed it into the cap and then used a brush or toothpick to apply it. It's too thin at first, but it doesn't take too long to start drying enough that it becomes more like regular touch-up paint. Then it's tractable. There were a lot of rock chips on this car, and some burnished-off bits along the driver's door edges. And the scrapes on the right side. The color is a close match, and if I block-sand some of the bits I applied it should end up looking pretty good.

A bit of acetone on a rag removed the schmutz that had gotten into the paint here and there. Primarily grease along the fenders and by the antenna from working on the car. The car looks pretty sharp! Shiny, and not even waxed yet.

With the home stretch in sight I washed the two remaining carpets and hung them out to dry. They came out pretty good. My boy helped so it took longer than it might have.

Thursday, March 30, 2006

Another lovely day. Finish today? I block-sanded some of the more exuberant applications of touch-up paint from yesterday, using 600 grit wet sandpaper. That helps a lot.

I then spent the next several hours detailing the car. Gluing back loose cloth, cleaning seats, installing cleaned carpets, vacuuming, cleaning off the door frames, etc. Tedious, but the car's sure looking good! It took a lot of scrubbing with acetone to get the unsightly rubber stripes off of the door frames. I then sprayed silicone on the door rubber so that it won't stick again.

The 'new' carpets are a lighter shade than the old, and to my eye don't look as good even though they're in much better shape. The tunnel cover piece from the donor is different in that it has holes in it for the seatbelt track attachment point, whereas this car has the mounts further forward, so it's of no use. I'll send the old carpets with the car so the new owner can choose the tradeoff between color and condition that he prefers.

Waxed the car. Glued a patch behind the small tear in the top of the rear seatback where the sun weakened it.

Done, except for the hood star (which I am waiting for). (OK, nothing's ever really done while it lives here, but I've reached the end of the list and the car's looking and running pretty good.) Ought to put the For Sale sign on it now. Need to take the pictures too.

Friday, March 31, 2006

Raining. Last night the brakes were squealing a lot on the left side, and the brake pad sensor light was flickering. So I jacked up the left front and found that one of the pad sensors was mangled, largely because that particular pad had the hole for the sensor in the wrong place! Weird. I drilled a new hole and installed another sensor. When I put it back I greased the backs and edges of the pads. That ought to address the squeal and the flickering, unless there's something else wrong with the other side's sensors. The 'new' lug wrench, which I used, worked great! I also jacked up the left rear and greased its pads too.

Had a look at the manual fuel primer pump. Not as leaky as I'd thought. A little exercise seems to have helped it out too. I pulled it off and had a closer look at it. Really quite a simple device. The big worry is that if it leaks fuel when you use it it's in danger of leaking air when you're not using it, and causing starting or running problems as a result. The knob on top screws down against a sealing ring that's on the shaft of the pump, it's very easy to see how it works and what kind of condition it's in (when off the engine that is). The air seal on this one was marginal, but still intact. Figuring that it was worth a shot, I got out my gasket punch set and punched a clean 3/4" hole in a sheet of Buna-N rubber scrap I got from a supply house. (They couldn't figure out how to sell me such a small piece, yet it's probably a lifetime supply for my needs.) Then I cut out a circle around this, with scissors (the OD is non-critical) and substituted this for the very tired seal that was on the pump. Fits fine, and works fine too. That should reset the clock on that pump.

On the test drive the brake squealing was gone. Car starts the same as before (as always, somewhat reluctantly), so it's not air entering the fuel system via the pump to blame. I do believe that the glow plug light is highly optimistic at higher engine temperatures, sometimes it doesn't even light long enough to see it. Glowing for several seconds anyway helps a lot. I bought a sacrificial 24mm wrench at the pawn shop to bend so that I can have a nice wrench for removing primer pumps. I'm tired of chewing them up using vise-grips. I also picked up that $17 diesel compression tester at Harbor Freight.

Saturday, April 1, 2006

Bent the wrench, used it to cinch down the primer pump.

Sunday, April 2, 2006

Put back the underdash panel. I think we're done under there! I put the windshield crack sealer on today. No real change, I'm next going to try to use the plastic sheets that were in the kit to trap the glue to fill in those pits.

Monday, April 3, 2006

Drove it to band tonight. Raining, car full of the family. It just purred down the road, smoothly on cruise control with the wipers doing their job, and I was feeling rather smug. With the underdash panels on it's nice and quiet. It shaped up rather nicely, I think. Will miss it, a bit. (Need to get to work on missing it.)

Tuesday, April 4, 2006

Dropped by the U-Pull today, and found three better door checks (the one on the car I already replaced is great, the other three are only so-so), an intact piece of wind lace for the driver's door, and a passenger-side under-dash panel that has the firewall-side black part. (This is a later addition, I don't think this car ever had that, and the face half attachment is clearly different.) Will look into swapping these items in, the underpanel may require cutting and gluing.

Wednesday, April 5, 2006

Put in the three door checks, greasing them first. (It took longer to get them out at the U-Pull than to install them here, largely because I didn't have the BFH at the yard. Those frickin' hinge pins... A heavy cold chisel makes a terrible hammer, but is better than nothing.) Only one of these three original door checks was broken, but all were 'weak'. They were the old roller style, the new ones are BB. Much nicer now.

Then I unscrewed the driver's B-pillar cover and pulled off the ratty windlace. I painted contact cement down the door frame and applied the salvaged windlace from yesterday. It went on very easily. Then the cover screwed back on. Much easier than I thought it was going to be, and looks a whole lot better.

Finally I took a look at the under-dash panel. The 'new' one has the black part stapled to the color part, whereas the old color part has holes for mating fingers on the black part. (The new color part is both the wrong color and has a different style of attachment to the dashboard. Not useful.) Once I'd used scissors to cut through the sound matting to separate the two parts I could see that the black part still had the old-style fingers on it, so it was merely a matter of pulling out the staples and installing it in the car. It fits perfectly, and should help cut down a little more of the engine purr. (It's a nice engine purr, but less is more, especially according to my wife.)

OK, now we're really done, except for the hood ornament. (Parts of which are due to arrive today.)

...And what did I find in the mail today? The hood ornament! Tomorrow I should be able to install it. Somehow.

Thursday, April 6, 2006

Pulled the hood ornament. Looking at the manual, the old epoxied POS, and the (partial) new star I now see what the huge spring to the bottom of the grille is about: the locking collar is missing (on both ornament assemblies!) and the heavy spring is what's holding the whole mess in. The old assembly had its heavier (of two) springs moved from the inside of the spring retainer cup to the outside of it (below), and the inner spring was extended and had a cotter pin through it to pin the outer spring in place. (The relocated spring is what normally puts tension on the star itself so that it stays wherever it's moved to in its socket, but its lack wasn't felt because the socket was epoxied together, presumably as part of holding on a snapped-off star.) Then the whole mess was spring-loaded down into the grille's hole by the long heavy spring. Without the locking collar what else can you do? I ended up just moving the old outer spring to the same place on the new (resulting in two outer springs, one inside the retaining cup and one outside) and used a piece of framing nail to pin it in place through the inner spring's hook as before. Then the whole mess was loaded into the grille's hole and tied down with the long spring, just as before.

Highly inelegant, but functional. And it looks just fine from outside. If someday a retaining clip turned up it could easily be made right as no harm has been done to anything, so that's OK, but it seems just fine to me as it is.

Done! (Have I said that lately?)

Now I just need to wait for the weather to clear enough to wash the car again and take the pictures. Then it goes up for sale.

Friday, April 7, 2006

A beautiful morning! I washed the car again and rewaxed the hood (as it was done poorly), then vacuumed it out and removed all the crap. Then I parked it off by itself and took pictures. Will probably need to redo the pictures at some point as it was too sunny for best results.

I then put the pictures into the web site and 'listed' it. After I came out of the dungeon I noticed that it had clouded over, so I redid many of the pictures, and picked up a few I'd missed. Posted ad on Craigslist, in Seattle, Spokane, and Portland.

Mercedes 240D, 1979, w/hitch & aux tank $2500 Spokane

Clean diesel sedan, everything works except the AC. Rust-free, has aux tank in trunk, 1000 mile range. Biodiesel? Has Racor fuel filter, but not hooked up. 302 kmi, See http://cathey.dogear.com/mb240dsale.html for more pictures, details. (509) 926-7801

Craig's list doesn't want you to list the same thing in multiple places, I had to change the ad each time to get past that. While I agree with not spamming the world, certain larger items (like unusual cars) are perhaps worthy of a little larger geographic interest.

Got one 'bite' on the car this evening, but it was a scam attempt. Sheesh!

Saturday, April 8, 2006

Another beautiful morning. I was told yesterday that the glow plug holes can be brushed out using a .22 rifle cleaning brush for a noticeable effect on cold starting, there was a considerable amount of soot in them when I had the plugs out before. May try this today, it's pretty easy to get the plugs out. I think I'll first have a look at the spare 615 head I've got so I can see what I'm facing. (The .22 brush may be best for the smaller pencil plugs rather than these series plugs. Do I even have a metal .22 rifle brush?)

By the time I made it into the woods to look at the spare head it has started to rain. Great. The spare head tells me that the .22 brush ought to work just fine. I looked, and I have two bore brushes that ought to work. A metal .22 one, and a larger stiff nylon one.

I checked the voltage drop on the plugs, and that dratted #3 was again over 2 V, versus the 1 V spec. So I pulled them all out and cleaned them. (A 13/16" box wrench is what you need, they're not metric.) They were much less sooty than the last time, the Italian tuneups seem to have worked. #4 was reluctant to come out due to soot build-up around the shank. Brushing out the bores didn't yield much. (I started with the little metal one, then swabbed out with the larger one and used compressed air to blow out the hole.) I swapped the one iffy plug with the one spare glow plug I have.

A prospective buyer stopped by and we went for a test drive. He's local, and interested in a biodiesel-mobile. The first real nibble!

I checked the starting current draw, and the glow plugs draw about 55 A, and with the starter it's 300+ A. Both numbers seem reasonable.

Sunday, April 9, 2006

Another cold start test. Passed, of course.

Thursday, April 13, 2006

Phone call on the car from BC. Guy seems quite interested in such a car, but it is located quite far from him.

Saturday, April 15, 2006

Listed the car on a biodiesel forum, http://forums.biodieselnow.com/, in its classifieds section.

Sunday, April 16, 2006

Another phone call (message) on the car, from Seattle area. He may send a local agent (a relative) to look at it this week.

Tuesday, April 18, 2006

Decided to try lubricating the speedometer cable to see if the continued small surginess of the cruise control is due to that. The needle is still a bit jumpy, especially at low speeds.

I used M1 5W–20, since my tube of speedometer cable lube was empty. As a light-weight synthetic, it should be pretty good in the cold. I jacked up the rear of the car so I could put it in gear, and dripped it into the open end of the cable as it ran. Then I took it for a test drive. The speedometer jumpiness is much reduced, as is the surging in the cruise control. I will need to do this in the 450 SL too, my only other example of a vacuum cruise control, as it also exhibits both symptoms. I had long theorized that since there was a large capacitor smoothing the output of the road-speed signal a bit of jumpiness in the sensor would be smoothed out, but I now believe that to be wrong. (You also have to account for the gain of the error amplifier, versus the output impedance of the circuit driving that capacitor.)

I then decided, since I had the instrument cluster out, to see why the lamp-test feature doesn't work on the low-fuel light. After much fooling around, even to the point of disassembling the cluster, and comparing schematics of various cars, I finally figured out that in 1979 there was no lamp-test feature on that light! (The only light missing that feature.) But since I was already all the way in there I added it. It just takes a diode and a resistor soldered to the back side of the big connector inside the cluster.

Friday, May 5, 2006

Though there have been enqueries, still no sale. With the warmer weather the car's starting a lot easier. Filled up the car again, 40 gallons over only 835 miles. 21 MPG, not that good even for around town driving. (I'm told that 25 MPG on the highway is fairly normal for these, though some [manual?] can push 30, so maybe 21 in town is reasonable. I guess I just expected a bit more.)

Saturday, May 6, 2006

Poor mileage? Reluctant starting? Time to do a bit more testing I guess. I took the car for a little test drive to warm it up to operating temperature, then while it was idling I cracked each injector line. Idle dropped significantly with each one, each reaction was approximately equal, so that's good. I then pulled the glow plugs. All came out easily and were equally sooted. Also good. It was time! I dug out the $17 Harbor Freight compression tester I'd picked up and tried it out. It goes together pretty easily, and I had no trouble putting together a set of its various adapters to get it into the glow plug holes. I connected the vacuum shutoff line to the main vacuum supply line in order to keep from injecting fuel during the test. I then did the test, eight compression strokes on each cylinder. All had equal results (modulo some badly-connected attempts where pressure bled away) of about 305–310#, which is to say above 300# on the gauge but not to the next tick at 320#. On the Bar scale I'd call it 21. The engine manual states that normal compression is 22–24 Bar, but that the minimum is 15 with maximum allowed variation of 3. I would call this good considering that the engine has over 300 kmi on it! This car's reluctance to start doesn't appear to be compression based. It is possible that the starter is slow, one or more injectors has a bad spray pattern (possibly only when cold), or the timing chain wear is to blame. All of these, if a problem, are fairly easy and inexpensive to deal with, the difficulty lies in getting a good diagnosis so that you're not just shotgunning parts at the car.

I have a used starter or two lying around, but they're of unknown quality. I wonder if there's a spec. for cranking RPM, and if so how the heck do I measure it? Probably the battery deserves a proper capacity test first, and the cables should be checked for excessive voltage drop.

While I was in the area I tightened up the alternator belt to eliminate the post-startup squealing. It was definitely a bit loose.

Now that the compression, though a bit low, is known not to be bad, the list of things to do that are all known to (and pretty much guaranteed to) improve cold-startability is now:

These are listed in order of ease. Before changing starters a bit more electrical testing would probably be in order. (Voltage drop, cranking RPM, etc. Make sure there are no smoking guns.) It should be noted that now that the weather has warmed up the car starts easily.

Saturday, May 20, 2006

Another call from the guy in LA. Has almost-offered $2000, would drive it back. Shall we take it?... (Sure don't want to.)

Monday, May 22, 2006

The contact cement I put on the patches to the sunroof panel and the rear seatback has let loose in the heat. I ought to try again using the 3M Super Trim Adhesive I've got left, if it hasn't dried up. If it can hold on a hood pad, it should hold up in the interior...

Clanking in LR hubcap. Rock or lug bolt? Will resolve tomorrow.

Tuesday, May 23, 2006

Was the drive axle retaining bolt. I guess it wasn't tightened enough! I've had this happen before on a car or two, it appears to be harmless if caught before the axle can pop out of the back of the hub on a chuckhole or the like.

Renewed the Seattle Craig's list ad.

Wednesday, May 24, 2006

Got an offer from the ad, in silver no less!
(20) 1 oz. uncirculated Fine Mexican Silver Coins and one (1) 100 Troy oz. Engelhard Fine Silver Bar
With photographs of the booty even. Thank you, but I prefer cash. I know nothing about silver values, especially coinage. The spot silver price of $12.60/oz for 120 oz of silver is about $1500. Unless the coins are worth more than their intrinsic value, no way.

I was wondering what was wrong: the last time I sold a vehicle all I got was offers of trade. Now I feel better, I guess.

In the afternoon we got another call on the car. Gentleman (from Seattle) will look at the web link (which somehow he missed) and perhaps call back.

Thursday, May 25, 2006

Still have the stupid car. Am considering renaming it from the Grand Experiment to the Albatross. (Done!)

Wednesday, June 7, 2006

It was suggested that MB diesel car prices are going nuts in Portland, so I listed it there again, this time making sure that the ad stated the car already had (expired) Oregon plates. (I'd gotten no nibbles the last couple of times I listed in Portland, so I'd stopped bothering.) Some of those PDX CL car prices are nuts, I looked. About an hour later I got a call on the car, but she hadn't realized the car was in Spokane. She has a local friend who might call to have a look at it. (Doubt it, though.)

Wednesday, June 14, 2006

Changed the oil. Should have done it awhile ago.

Thursday, June 15, 2006

Took car to Roy, thence to Vancouver for (I hope) eventual sale.

On the road we got a phone message from 'Gina' in Portland, she seemed real interested in the car (her first Benz and her first diesel). I also got other phone messages, and an e-mail or two asking for more information. (Didn't get the e-mails until we got back from the trip.) Was unable to hook up with the other callers, but did leave a few messages.

Friday, June 16, 2006

We made an appointment for Gina to see the car Monday when we reached Portland.

Monday, June 19, 2006

The Albatross has been sold! Gina turns out to be a nice young woman in NE Portland with a bunch of biodiesel-head friends who was interested in moving 'down' for financial reasons (trading in a newer Civic for the 240D, a bicycle, and enough cash to stake her in school) and really liked the idea of owning her first Benz, and her first (bio-)diesel. She liked the interior room of the car, the more upright (and higher) seating, and the fact that the car did not scrape in her steep driveway (unlike the Honda). She found the seats to be particularly comfortable. The 240D, though larger than the Civic, was not as ponderous as she had feared. The car will be mostly city driven, with an occasional highway road trip to visit family. (I told her to leave it in S except on the highway.)

She has mechanically-minded friends and family, and an older car held no fears for her. Her man once drove his VW bus to Guatemala, so I think the car will be in good company! The odd 3-way transaction (I never had the car in my own name, as we never intended to drive it for our own uses) did not bother her.

Of interest to me was the VIN, which I'd never examined before: 123.123-12-123356. Only 100 off from a very interesting number. Perhaps even more amusing would have been a serial number of 123123. Had it been either of these maybe I could have gotten extra money out of an eBay sale?

Thank you Gina. I have learned my lesson, and intend never to do this again.

Tuesday, June 20, 2006

ORDOT gave her no trouble, the car is already plated. We delivered the car only yesterday. She called when she had trouble starting, but before we could return her call she'd whipped out the owner's manual and followed the starting instructions therein. No problem starting then. By the time we could call her back she was already street-legal and on the road.

End of story? I hope so as it should be her story now, and I hope it's a good one! I deleted the Craig's list (and other) ads.

Friday, June 30, 2006

Gina called wanting to know if the oil had been changed recently. (I'd been meaning to call to see how it was going, but she beat me to it.) She took it in for a once-over before a holiday trip, and was annoyed to find that the shop did not change the oil. Some sort of a miscommunication there. They did adjust the valves thinking to eke out a few more horsepower, but there was of course no change. They did do an alternator belt adjustment, and replaced a missing bolt... (???) As the holiday weekend is upon us, she couldn't find anyplace that worked on such cars that could handle it. I reassured her that there was only about 400 miles on the oil in it when I delivered the car, and that there was a spare oil filter in the trunk that could be used at any Iffy-Lube in a pinch.

Anyway, she said the car's working well for her (though a bit sluggish) and she's already sold the Honda. She's filled the tank with biodiesel ($100!), has put on new tires (the old ones were decent, but a bit aged) and is hitting the road this weekend. Enjoy your trip!

Thursday, July 20, 2006

Today at the U-Pull I found the correct arrow-less knob for the floor vent control. Too bad the car is gone!

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