I have recently acquired an 83’ 300SD. The car has 200k on the clock and a questionable service history. I am planning to bring the car back to snuff. I have done searches and have found your discussion very helpful. My part in a similar Audi group has kept my beautiful V8 alive and in great shape. I think you will hear many questions from me in the next few months. Here are a few to begin with:…of course; thanks in advance.

-What parts suppliers do you recommend for the SD?...besides the dealer.

-At what speed should the engine run at when cruising at about 65? The rpm gauge in not functioning on the car but the engine feels as though it is running too fast. The trans was recently replaced with a used unit. Is it possible the wrong unit was put that has different ratios? The trans shifts into all gears.

-Should I post my questions in the Diesel discussion or the tech section?

-The turbo has a lot of shaft play. What is my best option for replacement and where do can I get it?

-I plan to start my work with a diesel purge, then replace all filters, install new injectors, rebuild the vacuum pump, timing chain, turbo, exhaust, and new shocks and needed suspension bushings. Can any of you tell me other items that are likely to need attention on this car? Or can anyone give any tips for the above repairs?

Thanks again
-Justin Lewis

You will love this car, I promise!

You will get more responses on the diesel forum than here, but some of us lurk in both places.

Parts are available mailorder here on the Fastlane section, at mbz.org, and other on-line places, search for mercedes parts on Google, etc. Prices here are pretty good. You can also get parts from a good independent shop, but they will likely charge you list, much higher than here.

Sounds like you have a plan, but I would not replace the injectors unless you are sure they need it. Start with a new chain -- if it hasn't been replaced, I'd bet it's stretched, but check, it's easy and can save you the cost of replacing a new chain.

Roll the new chain in BEFORE you do any of the rest, other than clean filters -- most of the problems I suspect you have are related to late valve and injection timing, those being hard starts cold, low power, and excessive smoke and diesel stink.

I would only rebuild the vac pump if it has failed and you don't have vac in the main line -- failure to shut off is usually dead vacuum line fittings, not a bad pump. Main line should have 17" vac or more at idle after a minute or two.

If the turbo has axial play and evidence of oil leakage, chances are the bearings are shot and it doesn't work properly. You can have it rebuilt at any diesel injection service, they all do turbos too. Cost will be in the $200 range for a "simple" kit (new bearing and seals, clean and balance) or $400 for a cartridge (new impeller, shaft, turbine, and bearings in a new housing).

I think the engine will be running at about 3200 rpm at 65 -- someone who has a functioning tach will correct me if I'm wrong. The turbo 617 can run up to 6000 rpm if you really push it (and I wouldn't with a 200,000 mile engine!) and will safely run at 4500 all day if you want. Benz runs them pretty fast.

Peter

__________________
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!