I have been hearing this slight noise from the engine bay. The noise sounds like a vibration. It occurs when I let go of the gas and let the car engine brake on 3rd gear, sport-shift mode on automatic tranny, at 3000 to 4500 RPM. I don't know if it is normal or not? Need info guys!! It only happens on this gear.

 

I get a high pitch noise from the engine bay on my 6MT. All it is, at least in my case, is back pressure from the intake or the lack of stress on the gears.

I'm doubtful we have the same noise since mine is in any gear.