Wednesday, March 14th, 2007 AT 8:42 AM
I purchased a used 2000 park avenue. When I drive above 60 mph I have a vibration which is felt on the seat. It is one which seems to come and go as if it's a harmonic type. It resonates as if perhaps tires are getting in synch. It sometimes seems to coinside with accerating and coasting but then again at times it isn't related at all. All motor mounts look good.

