Engine Vibration at 4k and above
 

My mechanic installed a new clutch disc and when I got the car back it had a vibration
at 4K and above. He did not installed a new pressure plate. What could he have done?

Don
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1965 912
1981 911SC
2006 Cayman S

Don't drive it until you pull the motor and inspect.

He didn't mark the pressure plate so it was installed in a different position. The engine is now out of balance, unfortunately. The best solution for him to rectify with this mistake is to have the flywheel and clutch disk sent to a shop that understands how to balance these parts. I would recommend Jay's Precision or Competition Engineering in California. While it's apart, it would be wise lube the clutch release bearing and check the crankshaft free-play.