The item below is copied from a post by elund126 from last year... My 2011 NonPP SHO has just started doing exactly the same thing. He has not had a definitive diagnosis and I thought that maybe someone else has come across this issue recently and might have a little more help for us...
This just started on my car. As I lightly accelerate and get up to about 1800-2000 RPM's, there is a louder humming/vibration that occurrs. It goes away when accelerate harder. It also occurs in while the car is stopped and in park. I push the RPM's to almost 2K and you can hear it inside.
To me, it almost sounds like an exhaust leak, but, if it were that, I would guess it would make the sound all the time. I had my wife in the car holding the RPM's at 2k and I rolled around under the car and under the hood and nothing was apparent.
To try and pinpoint, it seems to be coming from the front passenger side area of the car. You can feel it in the floorboard
My issue seems to happen most prominently when under very light throttle (1500-2200rpm and 30-40mph) I might be crazy but I also feel like since the sound has been audible there is a slight lack of power. Any advice or comments would be greatly appreciated.
