I have a 2004 GM and after I turn off the engine, about 10 to 15 seconds, it makes a sound like letting the air out of a balloon and making it squeal. I have replaced the radiator cap becasue I thought it might be the pressure. Anyone with other ideas?


Thanks,Ron

It's probably just vaccuum pressure releasing after the engine is shut off. It's not causing any problems is it?

It does sound like some kind of valve that might be sticking for some type of vacuum. It does not cause any problems yet that I can tell. One dealer told me that when some of the A/C components get older that they can cause noises. Thanks for the information and comments.


Ron