Just bought an 01 with a 4.0L and an automatic. After 1 week of ownership, I noticed a "chirp" when the engine is shut-off. No noises while running, the sound only occurs as the engine is turned off. Took it to a mechanic and they checked and eliminated the following possible causes. Loose exhaust pipe, serpentine belt and accesories (ran the engine with no belt - noise still occured on shut-off), harmonic balancer, distributor shaft, flex plate and bolts, transmission (ran the engine w/o trans attached - still had "chirp" on shut down). At this point they think it is an internal engine problem. Anything we missed?