Rumble at Idle after installing new mounts
 

I changed the engine mounts yesterday (all three). I have a more noticeable idle rumble ONLY when in gear....when in park, or neutral it is as smooth as could be..

What should i do?

Thanks

The rear transmission mount should not be tightened until letting the engine run for a little bit at idle. That might solve the vibration/rumble.

What should not be tight, the cross-member?

thanks,

This one I believe.

http://www.koperformance.com/online_...art_112272.jpg

What brand of mounts did you put on the car?


M

Sachs Boge front

Phoenix transmission...

For Future Reference
 

Motor Mounts are on the Official DIY "List of Equipment that must be Factory".

If the Part does not have a Mercedes Part Number on it ,Return it.

Anything else is subject to Q.C. issues And/Or EARLY failure

For what reason should it be tightened only after idling for a while??

Did you take a test drive after doing only the engine mounts? ie, so that you could determine if it's the engine mounts or transmission mount.

I did the engine mounts last week, and not the transmission mount (plan to do it this week or next) and the idle was 100 times better in gear. Basically smoother everywhere, except MAYBE the top end. 5000-6000rpm
And I am not certain if it is rougher in the top end, or it's a case the the bottom and mid is so much smoother that the top end in relation feels rougher