I decided to take the TJ to work today and noticed when backing off the throttle a very loud and high pitched whine (not really a squeal). I narrowed it down to between 2000 and about 3500 RPM - under or over that it's gone. It's not coming from the drivetrain or transmission because I tested it sitting still in neutral. If I rev the engine to 3k and let off the gas it goes wheeeeeeeeaaaaaaaalllllll. I've got video of it but not sure how to post that. I searched around and found a similar post on another site - the suggestions were either the water pump, the oil pump, the tensioner pulley bearing or the engine bearings. Anyone have experience with this? I'm not thrilled about replacing a bunch of parts that don't need to be. Please if you can help me nail this thing down.