[Danmcquill]

I have a 94 Deville, with the 4.9l engine. It has developed a wierd squeaky noise that disappears when the AC is put to Auto? The noise is only there when the AC is off.

Am I about to lose the pulley? And then the belt as I am driving? Or is the car ok to drive as it is?

Can anyone help?

 

[Ranger]

:welcome:

Hard to tell from here. Could be a weak belt tensioner or a tensioner bearing, idler bearing or clutch bearing. It's gonna need more hands on diagnosis.

 

[ratmonster]

If the noise really is coming from the compressor, my concern would be that your a/c clutch is on it's way out. But like Ranger said, there's so many other moving parts it can be difficult to determine the actual cause. Sometimes I will use a length of vacuum hose as a stethescope of sorts,sticking one end in my ear and using the other to probe the pulleys individually. Sometimes it works like a charm, sometimes the results are dubious. However, it's a cheap and easy way to try to ascertain the cause of your noise.