Motor mount

[dghii]

A little long so please bear with me...

I currently have two Boxsters, a 2000S manual with 110K miles that I've owned for almost 5 years and a 98 5 speed with 118K that I picked up last fall to clean up, bring maintenance up to date and sell.

A few years ago, I replaced the motor mount on my 2000S with an OEM mount and like most, found a nice improvement in smoothness and shifting. The old mount was torn and after replacement, I hung on to it for no good reason.

When I aquired the 98, I could tell right away it needed its mount replaced as the car was a little notchy shifting, had more vibration at idle and a resonance at about 3K rpm.

Given I still had my old mount, I purchased the rubber insert from Aut_Az for $39 and pressed it into the old mount. I installed the mount in the 98 late last fall and although I did notice improvement (in shifting and no more resonance at 3K rpm) I still feel the vibration at idle. It's not terrible but given that I can go back and forth between the 98 and the 2000S, it is extremely evident that the 2000S is much smoother with very no real evidence of vibration.

I speculated that the difference may be in the aftermarket mount perhaps using a different material. I ordered an OEM mount and installed it today. First impression, no real change from the aftermarket mount. I was dissapointed and now am not sure what, if anything, I can do rid the 98 of the vibration.

Let me caviot be saying that the vibration is not terrible...there is just more of it compared to the 2000S. The engine in the 98 runs very smooth and idles like a rock with no evidence of rpm changing. As part of my work on the car, I have cleaned the MAF and throttle body, along with the Idle air control valve. Air filter and plugs have also been changed. The car runs great and there are no codes present or pending.

Should I consider changing the rear transaxle mounts? I've never seen anyone mention changing them with regard to vibration. Any other area I can look at or is this as good as it'll get?

[Jager]

Could be the flywheel... do you have the history on the vehicle that tells you if, and when, it was replaced?

[dghii]

This was a two owner car that did have some service records but no history of a clutch replacement.

Thanks for the thought. You may very well be right. I'd like to drive another base car to compare. I expect it should feel like the 2000S as the mounts are all the same.