Engine Virbrations @ 3,100 RPM in 4th & 5th
 

I have noticed an engine vibration in my 2002 986 (2.7L) when the RPM's are dropping and hit around 3,100. The vibration occurs in both 4th and 5th gears. There are no noticeable vibrations when accelerating, just when I let off the gas pedal and the RPM's drop. The vibrations begin almost exactly between 3,150 and 3,050.

I plan on replacing the Air/Oil separator in the next few weeks but I wasn't sure if a bad AOS could be causing the engine vibrations or not.

This 986 is mechanically stock and has never been tracked.......yet.

Thanks in advance
-Michael

It sounds like you need to change your motor mount. You are having a classic symptom of a worn motor mount.

That's definitely it!

After a little googling, one of the other common symptoms of a bad engine mount is the gear shift moving back and forth under acceleration, which mine does.

Thanks for such a quick reply, looks like I have a new weekend project.

Tip.
Job is much easy when removing the coolant hoses.
Good oportunety for coolant flush as well.

Has anyone had any experience with just replacing the bushing and not the whole mount?

The entire engine mount assembly isn't too expensive ($156), but it never hurts to save a little cash if I can just replace the bushing for $40.

The bushing assembly is made by Lemfoerder, but I haven't found much information on them. http://www.amazon.com/Lemforder-Engine-Mount-Bushing-Only/dp/B004PAG1DQ/ref=pd_sbs_263_1?ie=UTF8&dpID=51W21lsPdYL&dpSrc=si ms&preST=_AC_UL160_SR138%2C160_&refRID=0WRHKTF9W1G BYC3DCR8D

Is it worth the hassle of pressing in the new bushing or should I just replace the entire mounting assembly?

I used the bushing assembly and it worked fine. Tool guy at work
did it with a heavy duty vise. Good way to save a few bucks and the old
frame looks like it will never wear out.