Chirping Sound from A/C Compressor

This could be the result of a number of things. I would recommend taking the vehicle into your local dealership to be diagnosed. They should be able to assist you further and have a plan for addressing the issue. I can also look into this issue further. In order to do so, I will need some more specific information from you. If you could please send me your full name, address, phone number, the VIN for the vehicle, and current mileage via private message, I will be able to take further steps. Thank you again and I look forward to hearing from you.

Tricia, GM Customer Service.

Its most likely when the compressor is kicking on or off, but it shouldnt be that loud, like Tricia said take it to the shop. As a 2008 there should be some warranty and AC systems are just to expensive to just guess and throw parts at it.