B6 S4 4.2l engine vibration

[John Cody Forbes]

Got an S4 in the shop today with a __horrible__ vibration. It is 100% engine related, is not effected by clutch position nor road speed. Noticeable at idle and get worse as you increase revs, so much so that I am afraid to take it beyond 2000rpm. It is not a misfire, engine runs well. No CEL. Everything on the front of the engine looks ok, harmonic balancer runs true, etc.

The only thing I can think of is that the dual mass flywheel center bearing let go and the clutch side of the flywheel is off center. Obviously the cost of being wrong about that is significant.

Any ideas/input/btdt?

-Cody (mobile)