Hey all. I'm stumped and a bit frustrated today. I have a cold start chirp (94 XJ 4.0 HO) that I've done alot of work to find. So far I've replaced the alternator and water pump, checked all the pulley bearings, then decided to start it with the belt removed. Still chirped when it's cold and it's rhythmic with the engine. I then moved on to replace the distributor, harmonic balancer and front main seal. Still chirps when it's cold. The chirp accelerates with the engine and disappears after 5 or 10 minutes of running when the temp comes up. I've been all over the engine with a stethoscope and can't seem to pinpoint it. My next thought would be to inspect the rod and crank bearings but the engine only has 260k kilometers on it (160k miles?), oil pressure is great, there's no knock, and the chirp seems to be coming from the top or front end on the passenger side. The stethoscope didn't help me pinpoint it but I can hear it a little bit clearer from the timing chain cover. Any ideas?

 

Technical questions belong in the technical section.

 

Oops. Sorry about that. I'm new here and still figuring out where to post properly. Thanks for letting me know.

 

Chirping normally comes from the rockers when they start to wear out.

 

Great idea. Thank you. I'll pull the valve cover off and have a look at them.