Yes could be the belt you could have a weak belt tensioner is the noise worse with the a/c on?
March, 29, 2011 AT 9:39 PM
I am not using air (live in Wisconsin). It happens when I accelerate and as soon as it backs down it stops. Leak in a hose?
March, 29, 2011 AT 9:43 PM
Sound's like you could have a weak belt tensioner that's what keep's your drive belt tight. If you have a/c on your car an it work's turn it on and see if the noise gets worse.
July, 18, 2011 AT 11:34 PM
Did you ever get this resolved?
November, 22, 2011 AT 9:01 PM
It seems to be known issue with resonator on the G6 HTCs. (G6performance. Com) Maybe because of the exhaust's size, anyway had the same problem, whistling noise under acceleration between 2000 - 3000 rpm but no other time. Checked belts, tensioners, etc, etc, no joy. No longer under warranty I had a Magnaflow 10424 put in and that fixed all the weird noise, just sounds good. Good luck!