Hi cheelam, I'm driving a 2011 Hyundai Sonata. I noticed that sometimes there is a low "growling" sound that changes tones when I rev the car, almost similar to the "airplane sound" of a badly installed car audio system but very low pitch. This is very random and normally noticeable when car is stationary or slow moving.

Hyundai SC says that the compressor needs replacement. Do you work on Hyundai cars? What is the estimated cost of replacing the compressor and is it complicated work (remove a lot of parts etc)?

Thanks.