Sab

I have recently had my tranny pulled out to fix a broken pinch bolt clamp, a tranny leak and in the same process my mechanic replaced the rear engine crank seal as well. We also replaced the TC bearings and put it all back together. I immediately noticed a strong vibration between 1800 and 2900 rpm in all gears and in neutral. (now I can't promise that it had no vibration at all before, but I also had a broken rear pinch bolt clamp). We lifted up the tranny with a support on the lift and the vibration got significantly better. So he replaced my tranny mounts and we tested the car after and it improved about 80%, but it is still noticeable.
Now the problem:
He disconnected the front flex plate and he ran the engine alone and it aparently still vibrates the same.
Does anyone have a suggestion what could cause vibration on my engine?
My engine has some history since the local shop was so kind and pour sand in my original engine and ruined it. They bought a used replacement engine from a fellow rennlist member and installed it. It ran fine for 200 miles and the front pulley fell off on the Turnpike (That was a nice touch by them...). Besides all the pulleys falling off, the timing belt slipped off (in idle) just before the engine stalled. They at that time ensured me that the engine survived without any damage. And as anyone could probably imagine I could not get out of the shop fast enough and vowed never to bring my car back there.
Does anyone have some suggestions as to how I start troubleshooting the vibration on my engine? I assume it will not improve engine life to run with a significant vibration...
Thanks,
Sab. <img border="0" alt="[cherrsagai]" title="" src="graemlins/drink.gif" />

Chris

Sounds like you have had a boatload of issues come you way, hope you get it all fixed and running soon.

As for the vibration have you checked the engine mounts ?? Does the engine rock from side to side when you blip the throttle ? Is the pan hanging way lower than the x-member ?

Chris

Sab

Thanks Chris,
my mounts are about nine month old. I was just done doing the mounts, water pump, timing belt and a bunch of other pricy items before the first shop ruined my engine.
regards,
Sab.

Shark_gts

Vibrations aren't nice in 928's. Sore of spoils all of the fun.

1. Rotating equipment - could the damper pulley be damaged?
2. Vacuum leaks can cause vibrations, and check proper operation of the tuned resonance flap.
3. Engine miss - ignition.