Lumbergs Lackey....MmmmKay

Hello all,

My 90 S2 Cabrio is having severe idle vibration. When accelerating or just driving around it runs like butter, almost new actually. Its just when idling it vibrates so much that the dashboard actually seems to be vibrating.

Now I had my motor mounts changed about 7 years ago but the car only has 36k miles so I doubt its from driving. I only put about 1k miles a year since I bought the car from the first owner in 96.

Does the S2 have a balance shaft belt that needs to be tightened?

thanks

V2Rocket

Yes you have balance shafts, but typically they don't present themselves at idle speeds.
More prominent in effect around the 3000rpm range.
Idle is most probably your engine mounts having gone bad (what brand mount did you use? Genuine Porsche, or aftermarket?). What is your idle speed? I believe an S2 wants to idle at 840rpm.

Lumbergs Lackey....MmmmKay

Thanks for the info. I'm not sure if they're aftermarket or not, I paid a pretty penny for the service along with clutch and other things, but so many shops are shady these days.

My S2 usually idles a bit higher than that, about 150 rpm higher. At 3000rpm the engine is butter smooth.

So probably engine mounts? How can they go bad without really driving the car regularly? Should I drive it more?

V2Rocket

Bad engine mounts will still smooth out by 1000-1100 rpm just by touching the throttle a little.
The 944 engine fully dressed is approaching 400lbs...it's pushing down on those mounts whether it's driven or not

porscharu

With that said, you should definitely drive it more.

culture

sounds like motor mounts to me. if you are a receipts kinda guy, oem mounts are over $200 a piece. if yours were less than that, then they probably were aftermarket.

ps. good to see you still have the white cab. first 944 front/968 rear i had ever seen.

Lumbergs Lackey....MmmmKay

Thanks Culture its much appreciated. I've had her so long now I wouldn't know what to do with the garage space

Plus, since putting in a complete champagne leather interior and wheel I like sitting in it lol.

The mounts were more than $400 but my shop is really expensive. I've get some new mounts, guess her sitting for months isn't good for her.

Thanks gents