Hello, I have a 2005 Pontiac Grand Am, v-6. The serpentine belt chirps when it is idling, and when the rpm's are raised it squeals. I've had the belt off 4 times today, checking each pulley, and the tension is good and tight, the belt looks good. The noise seems to be coming from the A/C pulley area, but it makes the noise when the clutch is engaged and when it is not. I replace the idler pulley that is next to the A/C, just to make sure. Any idea's?