Vibration when Stopped in Gear with Foot on Brake

Question

1998 Mercedes E320 (57,000 miles)

My car has a bad vibration when in gear, but stopped with my foot on the brake. The vibration is not there in neutral, park, or reverse.

This only happens before the car warms up. After it warms up, it runs really well. It also runs well when it's cold and the brake pedal is not down.

1. What could be causing this vibration?
2. How do I investigate the cause?

Answer 1

Had the same issue in a VW Golf(1995 model). The car would shake violently when stopped a redlight. Tore the whole car apart and found out that my engine AND transmission mounts where very loose, got new mounts and tightened everything. So check the mounts, mechanic said that on older vehicles those tend to be the culprits.

Answer 2

Pre-1999 E320 rings a few bells with me on transmission issues.

First thing to do - CHECK OIL!! make sure it's got enough of the stuff. This can help, if it's suspiciously low, this could indicate a leak.

Get a mech to check the TCU or ETC - these cars are known to leak oil / fluid into this control unit which can affect transmission.

The other thing is the clutch if it's old it can cause this effect when cold. If this only happens when cold, in gear and when not moving (ie clutch down) this is another thing to check.

I'd advise getting a mech to check over transmission control and the clutch, engine mounts are a possible cause, but if they are loose / damaged I begin to wonder if the car has had a hard life!...