My car suffers from a really bad vibration that begins at about 5500rpm and gets pretty serious by 6000rpm, regardless of throttle position. Even when I bring the revs up super gently to 5500-6000, the vibration is bad. I can feel the resonance throughout the car and even through the seat. This is completely engine speed dependent. Any clues as to what could be causing this?

 

Dude, thats fukn wierd!!!!!!!!!

 

what do the vibrations feel like? does it feel like fuel cut? do you have any error codes?