My '06 GT has an engine vibration that happens at ~3,100rpms. It's been there from day one, but I've just recently really pinpointed when it occurs. It is not earth shaking or anything, but enough to notice. It isn't there below or above those rpms, and it happens whether standing still doing a neutral rev, or while moving in any gear from 1-5.

I've pretty much ruled out driveline issues, since it is rpm dependant. It seems like this is the magic number for some sort of resonance. Could it be an engine mount issue? Is it normal, or should I take it in for a quick look?

 

It`s your bottom pulley the harmoic balancer my 95 had the same porblem

 

Thanks. I'm taking it to the dealer on Tuesday. Is this pulley replaced with an underdrive pulley set? Just curious, since I'll probably be doing that down the road.

 

yes