Solaceye

My 2008 S550 vibrates when it's in drive and my foot is on the brake. It's worst if the AC is on. It fine when in park and neutral. When I noticed the vibration I had my mechanic change the engine and transmission mounts, spark-plugs, crank case vent valve and transmission fluid. Picked the car up and the vibration is still there. Any suggestions?

Since purchase 4 months ago at 86,500 miles: Rotors, brakes, front calipers, right airmatic strut, front axel, windshield wiper pump, tire sensors, alternator, starter and auxiliary batteries all changed.

SilberGrau57

Perhaps accessory belt/serpentine belt or pulleys/tensioners? Or the AC compressor/clutch. You said it got worse when AC compressor kicked on.

regiment1

I originally was going to say Motor mounts! But you already did those....

tbilisi79

I have the same buzz in the steering wheel at idle and take off. Its most noticeable taking off. I wanted to change mounts next, but now IM not sure. The engine doesnt exactly jump put doing the brake test.

Senecat

It's the mounts. Your mechanic screwed something up.

kdr

Were the front CV axles replaced? perhaps with aftermarket parts. I have this issue on my W211. I replaced the CV axles and motor mounts at the same time and the problem started. Thought I got bad mounts, even installed another set, but nope, after some research, I found out this can happen with aftermarket axles.