GMC Repair: 2003 Yukon rough idle with AC, decarbon, loud noise

Question
I get rough idle with AC on and intermittantly a very loud noise. The AC works fine and is still very cold. Could this be a bad clutch or bearing?
Thank you, Scott

Answer
Try turning on the A/C and flooring the gas pedal to about 4500 rpm. If there is a loud slapping noise when the engine slows down then your compressor is sludging up and needs to be replaced along with the belt and tensioner.

Also an engine decarbon will help with the low idle with the A/C on.


I am sorry that it took so long to reply, it has been very busy around here.