I would have to concur with the balance shaft theory. Mine was out 180 and it would buzz so badly that my hand would go numb if I left on the shift ****. The definitive diagnosis would be to take the BS belt off and then drive it. From what I have read the motor is actually fairy smooth without it, compared to being out of adjustment.

 

Thanks ckathens.....looking forward to it!

car_slave - thanks for the tip. I'll pass that on to the mechanic tomorrow.

 

Wanted to add some closure and gratitiude to this thread. My 944S is back home after nearly a month with the doctor. Among the repairs were:

New motor mounts
Fixed driver's side door lock
Several dent doctor repairs
New hood strut
New coolant overflow tank

Most importantly, my vibration is history.

Thanks to your insight and advice, the problem was traced to a missing Woodruff key in the upper balance shaft. Now, 4000 RPM is a good place to be.

Appreciate everyone that contributed to the thread and got me back on the road.

Tim

 

So the belt pulley was slipping on the shaft giving the same indications as mounting the pulley 180 degrees off. Missing, somebody was in a hurry and did it wrong!

Glad to hear it was not the clutch.

 

Exactly - the pulley was only held in place by friction. It was approximately 90 degrees from true.

 

aaaaaa, memories of pain........

glad to hear you got things worked out. your S is a beauty - i'm envious.

 

Thats right Joseph, I have your pictures bookmarked for good reason! Just think how much good your pain has done by scarring the rest of us into checking the tensioner. Thanks Joseph