Chevrolet: Chevy rattling AC, 2000 chevy cavalier, chevy cavalier

Question
Hi...
I own a 2000 Chevy Cavalier and lately I've noticed a rattling noise coming from under the hood. Basically, as the car runs, it sounds like a metal on metal rattling noise. The noise completely goes away when I turn on the AC, but comes back as soon as I shut it off. When the AC is on, it is good and cold and the car still runs fine. What could this be? Is it bad to let it go for too long?

Thanks,
Neal

Answer
It sounds like the A/C clutch or bearing is gone.

When the A/C is off, the pulley sprins free on the shaft and is the bearing is gone its gonna rattle. When the ac is on, the clutch is engaged and it doesn't spin free.

Unfortunately, with most GM cars you will need a new compressor.