My 300E idles rough in gear when you come to a stop n go situation. It smoothens as you take off. The dealer replaced the voltage regulator($296) but that didn't stop it. Its odd coz the whole car shakes. It also does it whether the engine is hot or cold. A year ago, the M16 motor and the air mass sensor was replaced. Cost me a ton then. Any suggestions anyone. Please help.

I had similar symtoms with my 91 3ooe. I had a vibration come through the whole car in park & Drive. It turned out to be the Engine mounts. These mounts are both fluid and rubber. After a time the mounts collapse and all engine vibrations go right through the frame of the car. I hope this helps. Let me know.

I am having a similar problem in my 1991 420 SEL. In idle the whole car shakes slightly and very noticebly whether cold or hot. Acceleration is good and the engine is smooth at higher RPM's. Could I also be having motor mount problems?