My entire 300sdl will shake when at idle.
I brought it into my Mercedes certified Mercedes Mechanic.

He check the car's compression, injector pump, listened with a stethescope etc, but could not find any problems.
He stated my motor mounts were shot, and that that could be causing the car to shake more than normal.

I replaced the motor mounts, but still the car shook at idle.

I then had all the filters replaced, and still the rough idle persisted.

My mechanic said he sees this on higher mileage diesels, but was the first time to see it on one with 80k that was not in need of some sort of repair.

Is he missing something? Has anyone had this problem and has success at correcting it?

I love the car, but the shake at idle is unpleasant (to say the least) and seemingly out of character for this car.

Thanks

Did he check the timing chain stretch? If so, the engine could have bent connecting rods.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

I will ask him Monday about the timing belt. What does a repair like that cost? timing belt and or connecting rods?

I have to see im Monday, as the turbo seems to have stopped working. The car has no power when climing hills, and smokes like crazy.

My mechanic made an adjustment one time when it lost power, and it ran well, but now it is like it was, and I have no idea what he did. Is there an adjustment that can be made?

I has had the trap oxidizer replaced, does Mercedes still warranty the turbo like it did with the trap oxidizer?

Thanks

First your car has a Timing Chain!! Not a belt! I do not know the cost but the chain should be done first if it hasn't been done already. There is a small hose for the wastegate that could be faulty. Also there is a small vac tube that goes to a sensor to enrichen the fuel mixture when the turbo spins up. If the line has a crack in it, you will have simmilar results.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

What about a flywheel or harmonic balancer that is gone astray?

hey just a guess.....

Just something to suggest to your mechanic: I read about a problem exactly like this before and the general consesus was that the timing chain either had excessive stretch or had jumped a tooth. Excessive stretch seems more likely to me though.

I have an '87 SDL with 105K. I get some rumble and shaking when idle; I just attribute it to the diesel engine. Yours must be excessive. On the freeway, I get a vibration that I feel in the steering wheel. I had the front wheels balanced but it may be sonething else. I do not have a front encapsulation panel so the road noise on the freeway, especially, is probitive. I also get some wind noise around 65mph from the front passenger door/window. I'm going to take my car in and get this checked out and buy an encapsulation panel ($270.00, yikes) for the noise.

I took my car to the mechanic this morning. The turbo problem was traced to a vacuum hose that also goes to the transmission.

The smoke is being caused by a bad EGR valve, have not had replaced yet, so will see when when he replaces it Wednesday.

He said the timing chain is ok, and that it will make a noise when it gets stretched.

So, two out of three, would love to get the shake fixed though.

Does this all sound correct?

Thanks
Chris

IF you trust your tech, YES.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Update:
I was driving today around town, car ran fine, plenty of power, even off the line. THEN, I went on an on-ramp to the freeway, and it was a whole different story. Absolutely no power.
I took it back to my Mechanic, he check it out quickly (till he could look at it closer), and now suspects it might be the catalytic converter Mercedes installed, or a problem with the turbo boost.
I will take it in earlier(tomorrow) any advice. How common is it for a catalytic converter to go out/get clogged? The trap oxidizer they replaced worked fine, AND it was warrantied by M.B. I don't think MB warranties the conversion. Am I correct?

Talk about bad karma! last evening, I went for a long drive and at a stop light, on the way back, my 300SDL went into 'bucking bronco' mode. It felt like the engine was 'missing' (maybe not a proper term for a diesel). Once I started driving, it was OK. This morning when I started the car, it started doing the same thing. I already had my 500E at the mechanics, so I took the SDL in also! I thought the car would stall out on the drive over, but the ride smoothed out once I started driving it idled OK. My mechanic thinks the bearings in the tensioner may be breaking up. He says they can fall to one side and cause that sort of problem. I'll post the actual results once I find out for sure. I had my timing chain checked about 4 weeks ago. He said it looked OK.

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Mark Herzig
1992 500E (82,000 miles)
1986 300E (181,000 miles)
1987 300SDL (104,000)


[This message has been edited by Mark Herzig (edited 05-04-99).]

My mechanic diagnosed my problem to be the turbo. He said that when he took the casing off it was frozen stuck? Is replacing or rebuilding the only way to go?

As long as the shop has a good reputation, I say rebuild!

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Just remember the turbo is there to provide boost for more power, doesn't affect idle quality!! So if the engine idles rough with a good turbo then it will rough with a bad turbo.