Driving me crazy!!!

[adm261]

First things first. I have a 1998 explorer xlt just passed over 69k, 4.0, 4x4, with AC . I've been having this squeal-chirp noise coming from the engine compartment on start up (and in drive until motor warms up), only when its cold or been sitting for more then an hour (give or take). I Went to the local advanced auto, picked up the idler pulley and the tensioner assembly, Put it on and bam still doing it. :frustrate: :fire: I have read and seen it could be multiple things. But what i tried was the two main things. Can anyone help with my obnoxious problem?!? Much appreciated!!

 

[nitrodude]

Did you get a new belt?
Get a good quality serpentine belt.
If you have an aftermarket high output alt, look into gator back belts

 

[adm261]

I have heard both that works and doesn't. I will give it a shot tho. Thanks for the help

 

[Lizard]

It is your camshaft position sensor synchronizer. They will start chirping when they are getting dry internally. The shaft that goes into the block looks like a distributor shaft. It sits under the coil packs. You got off light just replacing the idler pully. I replaced the waterpump before I found the problem. I put a stethoscope on the WP and swore it was the problem. New pump in same chirping. Then listened to the Cam PS and there it was. Then the noise went away before I replaced the part.

 

[01STrunner]

I have been chasing the same problem. So far I've replaced the belt and tensioner pulley.