I have a 2000 Chevy 1500 4x4... starting yesterday, whenever I turn on the AC it smells like antifreeze. It gets worse as the vehicle heats up, and its bad enough I can't use the AC. I have a 30-minute commute, and its 105 degrees. HELP! I lifted the hood...nothing looks out of place. No warning lights, and the coolant/air filter have been recently serviced.