Let me first say hello to everyone, this is my first post.
I own a 1991 350SD that burns approx. a quart of oil per 500 miles.
I'm the 2nd owner and have owned it since it was 4 years old. I bought it as a "Signature Class" car from Mercedes-Benz.
At 50mi, I had the engine overhauled under warranty(I'm sure everyone here has heard of this story by now). The car seemed to drive perfectly until lately. The car started smoking pretty bad on accelleration, and it started sucking oil like crazy!! It was all going out the tailpipe!
I removed the head and sent it in to the machine shop for a complete overhaul(the car had 120mi at this point). Now it's smoking less, but just a little less. I was wondering if the oil burning had anything to do with the turbo, or ALDA, or Vacuum Pump????
Can anyone please help? Any opinions?

hello. I have a 350sdl, 90K so far so good.

How many miles on yours? what kind of oil, what kind of driving? usually the problem is in the block, rings, rod, etc.


:Real engines don't have spark plugs!!

You need to be careful with this one. If you get enough oil in the combustion chamber you won't be able to stop the engine even with the key off. It will just burn the engine oil. My brother had VW Jetta that had a similar problem. You'd be driving and all of a sudden it would start bellowing black out the tail and you had not control over the RPM. It never really reved up ( running a little rich I guess) but you couldn't shut it off. I forget what the main problem was. I'll check with him and post again. It seems like it had considerable blow by, the oil would puddle in the intake manifold eventually going into the engine all at once.

Wow! What a slow forum this is!
I posted this a LONG time ago and it's still on the first page!
Anyhow, the problem with my 350 has been fixed, it was the turbocharger.
The car consumes NO oil, and it drives better than ever!

-Mapleleaf.

I prefer to think of it as a less cluttered forum :wink: .

Glad you got the problem sorted out, and just out of curioustity, how many miles were on the turbo?

Mapleleaf:

How much research have you done on the history of the early 3.5 L diesels? When I read your post, I anticipated another to follow advising us of catastrophic engine failure. The problems with these engines is in the lower end, not the top end. This is what FJBertrand is referring to.

While you are now pleased with the way it is running, I strongly encourage you to do more research on the 350's, in the event you may want to make some changes while it is running.

Sincerely,
Scott