I've been looking on and off for about a year for a clean '86-87 300SDL. Finally bought one last week. Patience paid off. Bought the car from the second owner. Car has verifiable milage of 107K and near perfect paint, body, and interior. Took the car on my weekly road trip from the DFW area down to central Texas - a round trip of about 600 miles. I love this car, and it loves the open road. Awesome! This is the first MB I've owned. I'm already very attached.

Of course, shear age has taken some toll on the car. Most of the problems seem to be with tired vacuum hoses and related components. With help from past posts on this forum I'm going to troubleshoot my door locks later this week. I've already learned a lot about the car from the knowledgeable posters on this site - Thanks!

I've heard that the timing chain should be replaced at 100k miles. What is the prevaling opinion on this board? Any other major maintenance I should consider. I've already read the posts on the air bag. I think I'll keep the $1800 and hope for the best.

I read some posts regarding vacuum pods that control dampers in the ACC, so I've educated myself some on this topic. ACC seems to work OK with one exception. At all settings I get cold air (vent) from the center vents. This is a big problem since its starting to get cold. I assume that there must be an actuator that controls the routing of air between the heater box and cool air plenum to these vents. Is this particular actuator easily accessible or is it one that requires removal of the whole dash?

I'm also looking for a service manual (paper). I bid on one last week on ebay but it got away from me. I also noticed that you can buy service manuals on CDs on ebay. I assume that most of these are bootleg copies of the official MB versions that appearently sell for $120 or so. Has anyone bought one of these off ebay? I really need some wiring and vacuum diagrams.

I have other questions but I'll post them separately.

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'87 300SDL
'96 F250 Crewcab PowerStroke
'00 Kubota L2600
'66 Malibu ragtop (SOLD, sob)
'01 BMW M3 ragtop

Bought a CD on ebay a few weeks ago for about $12. I assume it is a copy. It's not as convenient as a paper manual and a little hard to read but it works.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

CB Graves,

Not sure about your model, but many older Mercedes had the center vent only serve as either an A/C vent or a fresh air vent. They did not provide heated air. If it got cold you would just close them. I am not sure what the convention is with the newer cars, but I miss the blast of fresh air the old ones used to give out of the center vent. If you have a manual (owner's/operator's manual) this will be spelled out more or less clearly.

I am also not too familiar with the chain replacement philosophy, but unless you have a single row chain on that engine I would not expect to have to replace it at !00 kmiles. On the older cars the manual actually tells you to compensate for chain stretch by installing an offset Woodruff key in the camshaft/chain sprocket keyway. I think they come in 2 degree increments of offset, up to 8 or 10 degrees. I am sure someone will pipe up with more specifics on this subject for your car.

Good luck and sounds like a great car! Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Only cold air comes out the center vents. Warm air comes out the side vents, windsheild, and floor vents. Ditto for the vent at the rear of the console -- close it in the winter, it only blows cold air.

Usually, nothing comes out the center vents if heat is called for. If the servo goes bad, nothing comes out at all. If the conditioned air is too cold for you as the ACC works, just close the center vents unless you want AC. Mine close off and stop blowing when the heat comes on.

If cold air blows out all the time, someone may have jammed the center vent actuator open due to a failed servo or inadequate vac -- you will need to get a MitiVac hand pump and check. You can attach the MitiVac to the supply line (green) in the engine compartment and pump the system down. If it then works correctly, fix the vac supply problem. If it won't pump down, you have a leak in the system. The connection for all the servos is behind the glove box, I think -- you can test all of them from there.

I have found, on both my W124s, that the temp dial must be set rather high, they both run cold. Try that before diving into the vac system.

Timing chain needs to be changed when it is stretched (worn), not by milage. If the PO changed the oil regularly and you don't have starting or smoke problems, you probably don't need a chain. Checking this one is a PITA, only costs the price of the chain and half an hour's labor more to replace than to check, so replace it if it makes you feel better. Not usually a problem on the 603.

You probably have lots of dead vac line connectors. Also may have dead actuators for the EGR and turbo air recirc, niether a problem unless they leak badly. In that case, the ACC will blow only up the windshield (unless diddled with) and the tranny will shift VERY hard.

Lovely car, my brother bought one last year, too!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!