2000 E320, car vibrates in reverse, drive at idle
 

I have a 2000 E320 with 120K miles. Car vibrates at idle when the shifter is in R or D. Turn AC on makes the condition worse. It runs fine without any problem. Changed the plugs and wires made no difference.

Is there a idle control module on this car? Where should I look?

Thanks
Bob

Sounds like motor mounts and or transmission mounts

x2

To test this, hit the throttle cable and the motor move alot if the mounts are bad.

Or just visually inspect them for cracks or alot of play using a long flat screwdriver carefully.

x3. Use a big rubber bushing between floor jack and oil pan and lift engine 1/4". See if vib is gone.

If still there look at the AC comp for drag.

this will be motor mounts no doubt.