Automotive Air Conditioning Information Forum

People,

1987 Sunbird, when I switch on the ac button to activate compressor there is immediately a loud screeching sound from the comp area. It stops after about 7-8 seconds. Vents put out ice cold ac. Then, every about 5 minutes the sound comes back, then again, goes away. Could it be the loose ac belt needing tightening? Maybe low on compressor oil?

Thanks, people.

Noquacks wrote: Fri Oct 02, 2026 5:10 am Could it be the loose ac belt needing tightening?

That should be easy enough to check.

I might pull the belt, and check any tensioners and AC clutch pulley bearings for drag or noise. And maybe install a brand new belt.

Cusser wrote: Fri Oct 02, 2026 5:51 am

Noquacks wrote: Fri Oct 02, 2026 5:10 am Could it be the loose ac belt needing tightening?

That should be easy enough to check.

I might pull the belt, and check any tensioners and AC clutch pulley bearings for drag or noise. And maybe install a brand new belt.

Thanks, Cusser. Good tips. Will try those checks this weekend!

I tightened the belt a bit, actually, to the max setting, which I thought was not a good situation for a belt to tight on the max slider notch. Started the car, and the squeal almost disappeared. But i watched the belt as it turned with ac on, and the upper edge of it was wobbling a distance of say, 1/2" up/down. is that normal? It would indicate the belt could be stretched, right? Especially even with it being tightened to the max arc setting.