My 2001 BMW X5 with 168K miles and my AC is not as cold two weeks ago. When I start and check the ac compressor, first ac compressor is not working but after drive ten minutes I feel the cold air working because the temperature gauge is dropping. When I park the car and engine running, ac compressor kick off and on. I can hear the sound when ac clutch is on and off. Could someone tell me is the ac compressor is going bad or something I look into before replace the ac compressor. I can replace the ac compressor myself and let the shop remove and put back the freon after replace ac compressor to saved money. How much is the new ac compressor cost? I can get a new denso ac compressor for $329 with core return.

Thanks,
Uhenry1