944 S2 cabriolet with severe vibration
#1
Burning Brakes
Thread Starter
944 S2 cabriolet with severe vibration
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
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
#2
Rainman
Rennlist Member
Rennlist Member
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.
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.
#3
Burning Brakes
Thread Starter
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?
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?
#4
Rainman
Rennlist Member
Rennlist Member
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
The 944 engine fully dressed is approaching 400lbs...it's pushing down on those mounts whether it's driven or not
#5
#6
Rennlist Member
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.
ps. good to see you still have the white cab. first 944 front/968 rear i had ever seen.
#7
Burning Brakes
Thread Starter
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
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