Here's what you need to do:
Drive on level ground where you can safely get to the speed where vibration is a problem. Depress the clutch and let the car coast. Allow engine rpm to drop. Record whether the vibration continues.
If the vibration continues, its driveline vibration. If the vibration ceases its engine vibration.
If driveline vibration, remove driveshaft and u-joints. Take to light duty driveline shop and get the driveshaft balanced and the u-joints replaced. Reinstall and your problem is likely gone.
If engine vibration it could be from a number of things, loose flywheel, bad pressure plate/clutch, etc. You'll have to diagnose or take to a shop that specializes in diagnosis. Pay for the diagnosis separately from work actions required to correct the problem.
|