I posted this over on the corral and didnt get much help, maybe someone here can help me. I bought a 2001 supercharged saleen almost a year ago. It now has 20,000 miles. Recently something in the engine bay has been whining (besides the supercharger ) , which I initially thought was the belt slipping. However, I looked at it a lot harder when it started getting progressively worse. Here are the symptoms: 1. Noise sounds like fuel pump noise, but 10 to 15 times louder, with a slightly more screeching quality. I can here it from inside the car with the windows closed at 50mph. 2. Noise only happens at idle or cruise with throttle body closed, as soon as the TB cracks open or there is load it goes away. 3. Noise increases a LOT if A/C is turned on. 4. Noise is from back of supercharger, possibly behind/ in back of supercharger. Not from snout or belts. 5. The boost sender was loose, and I tightened it back up. This seemed to reduce the noise (might be just psychological), but it still comes on, mostly only when A/C is turned on. Has anyone else had this noise before? It is really worrying me and is driving me nuts. I am really type A about stuff being mechanically right with my car, and this is mystifying me.