[richtazz]

your rattling noise is the clutch going bad in your a/c compressor. The noise goes away when you turn the air on, because the clutch is engaged, eliminating the gap between the clutch and the pulley. It will require replacement of the clutch and pulley to fix. The squealing noise is one of a few possible problems. the serp belt and or tensioner could be going bad (possibly a result of the bad a/c clutch), and at the end of it's travel, the rack and pinion feeds pressure back to the pump, causing it to drag, which will make the belt squeal. You could also have a bad power steering pump or a bad rack and pinion. there have been a few recalls reguarding GM rack and pinions. check with your dealer to see if your car is affected. If it is, it may be a free fix, if not, check the afformentioned things.