'87 YJ Whine***HELP***
Ok so I just picked up my first jeep today, an '87 YJ with 6" shackle lift and 33" tires. The guy I bought it from was trying to track down the cause of a very high pitched whine that it makes when idling. It mostly goes away when you get on the accelerator but if you listen close at low speeds you can still hear it. The strange part is it doesn't start up until it's been running for about 20 mins or so. So far a water pump and clutch have been replaced. A buddy of his suggested that it was the pilot bearing which was changed with the new clutch, but it still makes the sound. So far it is just an annoyance but if anyone has any suggestions on what could be the cause or if it is leading up to a catastrophic failure in something please help me out.