Noise when the A/C is off.

Just bought a 97 Grand Prix a few weeks ago. So far everything has been great with it. Today it started making an odd noise comming from the A/C condensor it sounds like. The noise stops completely when I turn the A/C on. When I turn it off it starts up again. It sounds like a loose ratling metal sound. Any ideas what this could be?

I'm not sure, but my first guess might be the compressor clutch...

If, when you remove the serpentine belt, you rotate the A/C compressor pulley and it sounds like a bunch of sand trapped in grease in a rotating assembly, you have a bad A/C clutch ass'y. I still am yet to make this repair after letting it sit for a year, and I have not experienced any real negative effects. Price for a complete reman A/C clutch w/pulley for my 00 GT was about 40-50 USD.

Awesome. Will test the clutch when I get home, from a few other sites I posted on seems like this is probally the problem.

i just bought a brand new clutch plate/hub and bearing set (i dont like used parts) which also came with a new coil, for a V-5 compressor on a 95 bonneville and it was $122 for the kit and $22 for the tool to pull the clutch plate off. On that one the bearing is failing in the hub and the tension of the belt pulling from one side closed the clutch plate gap and was dragging the hub on the clutch plate.