I Own a 1989 Mercedes 420 SEL with 240,000.00 miles. It normally runs and drives like a new car. Last week we had a bad snow storm in Michigan and my trouble began while driving home.
The car began to hesitate and pull back. The RPM gage was going crazy from 0 to 7 and back and forth rapidly. About a half hour later the car stalled. If I put the key in the ignition, but dont start the car, the RPM gage begins to go crazy. Now the car will start, but stalls after a few minutes. I noticed that carbon is coming out of the exhaust. No one will even look at it for under 300.00 and I would have to tow it somewhere. If anyone has any troubleshooting I could try, I would appreciate it.
Thanks,
Mary

when it does run, is it running well or is it missing and sputtering. Need to determine first if it is an ignition (spark to the cylinders) or fuel related (fuel pump, relay, etc.) problem. When was last tune-up? Where are you located? Might need to get it to a good independent mercedes mechanic (Look under GOOD MB SHOPS forum for recommended indie in your area) to make the diagnosis. The tachometer (RPM gage) is just a reflection of engine acceleration. Once properly diagnosed, the people at this forum are a wealth of info on making repairs. The more symptoms you can describe here the better the experts here can help with diagnosis.

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65 190d sold
85 380SE sold
87 560 SL 180K
84 380SE 96K (mint)

Derryb,

It starts everyday and sits in my driveway and runs good. No missing or roughness. Then it stalls after several minutes. The day it started, it pulled back and forth. I have not driven it since. I bought the car from an elderly woman September of 05. I'm not sure when the last tune up was.

Thanks,

Mary

What do you mean "pulled back and forth"? When it is idling good what happens when you give it gas? Does it rev up ok? Or doe your problem occur when you try to rev it up? From what i read your problem occurs occasionally. Is his correct? Are there times you can drive it around the block with no problems?

__________________
65 190d sold
85 380SE sold
87 560 SL 180K
84 380SE 96K (mint)

derryb,

I have not been able to drive the car for a week. The problem began on my way home in a snow storm and got worse. It started to hesitate and pull back every few minutes. (like when you drive a stick shift?) then the RPM gage went crazy. When I got it home it stalled in the driveway. Now I cant get it to run long enough to drive it. It runs 2-10 minutes and stalls. Since it has been sitting for a week, it is starting to idle rough when I start it and let it run in the driveway, but normally I start it to let it run everyday until it stalls.

Thanks a bunch,

Mary

Hey Mare,

I would say perhaps contaminated gasoline, but I do not think that would cause the RPM needle to go nuts when the key was in.

$300. sounds very steep just for someone to look at it. You must live in a very large metro area, or west coast. Are you getting these quotes from the Mercedes dealer?

You may want to post what region you are in if you are comfortable with that. Someone here may can recommend a good repair shop to you. There is also a thread on here somewhere that you can actually look at yourself to see if you see a local shop there.

Good luck.
Carry on.