well i have an 88 with a 1990 s5 engine and tranny recently I have noticed a really bad vibration I thought it was a bent rim but after changing the rims It still has the vibration. I also noticed it only vibrates under acceleration and when you throw the car out of gear to stop at a light.any ideas I think it might be an unevenly burnt clutch or a driveshaft weight problem.

 

Check all your mounts. Transmission comes to mind first and check the U-joints for play.

 

Is it bucking in the rear?... Specifically during deceleration.

 

when cruising at low rpm in any gear like 2k and under it bucks other than that, no. but it doesn't vibrate when deceling at all

 

Check your oil level

 

****, could be a number of things.. diff mounts, tranny mounts, ujoints, etc.. in my case it was the driveshaft&diff mounts.. I have a kaaz 1.5way and it likes to lock up under light load, and buck and shake things lose.. maybe check around that area

Your symptoms are very similar to mine.. although my vibrations were probably a bit more violent..

 

The narrow range on the TPS is out of adjustment. On the S4 the narrow range TPS is in the footwell and on the throttle (IIRC) pedal arm. if satch or hailers comes in i'm sure they could tell you how to go about adjusting it back to the proper voltage reading.

 

^ The S4 TPS is on the side of the throttle body in the engine bay. It is located on the opposite side of the throttle linkage.

With engine up to operating temperature (FULLY WARMED) and car OFF. Turn the key to "ON". Go to the engine bay with a multimeter and probe the Green wire with a Red stripe with the positive (+) meter probe. Ground the negative (-) meter probe. Set the multimeter to read "Voltage"... Now there is a flat head screw near the TPS itself. Turn either clockwise or counter-clockwise ever so slightly. You want the multimeter to read 1.00 Volts. If it is .98 V or 1.03 V etc. it's no big deal. As long as it is pretty close.

Be sure you do this as quickly and as efficiently as possible. You pretty much do not want the car to cool down before you perform this task.

 

I could swear he said he had an S5 engine, but okay.

 

Oh **** good catch, i need to start reading more carefully.

 

I have an s4 tb and my car also vibrates at 30mph then again at 60+

 

Have you checked for a bent rim/tie rod?

 

Very true.

But then...

This ^ So, I'm going to assume you're using the S4 TPS.

 

If he got an S5 engine, wouldn't it be better to run a S5 TPs anyways, as the full range is needed to adjust the speed and therefore the amount of oil the OMP spews out?

The S4 got as known only narrow range.

 

Well, if he is using the S4 throttle body, he's probably using the S4 TPS... Which means he is most likely using the S4 wiring harness and associated parts.

 

No need as OMP is blocked off and am using s4 ecu and wiring harness and all s4 accessories

Bent rim I had one I removed it from the car and still has vibration I'm really thinking its the transmission mount because I can hear a clunk from the tranny every once in awhile when I shift gears

 

Have you checked the passenger side engine mount? These are prone to getting brittle and breaking due to the heat coming off of the turbo. If this is broken it may be leading to other vibrations as well.

- Nick