Driving me nuts!!!

[adm261]

Alright 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, only when its cold or been sitting for more then an hour (give or take). And its not the a/c unit. Went to local advanced auto picked up the idler pulley and the tensioner assembly. Put it on and bam still doing it. I have been seeing it could be multiple things. But those were the two main things. Can anyone help with my obnoxious problem?!? Much appreciated!!

 

[Runnin'OnEmpty]

You did not say if it's an OHV or SOHC engine,
but there's a possibility the trouble is the bushing
in the cam synchro drive.

Try removing the serpentine belt and starting
the engine for a few seconds. If the chirping
stops, then it's one of the other front pulleys.
If the chirping continues then it probably is
the cam synchro.

 

[Peck]

i have the same thing started after i got stuck plus a vibration under the truck only at certine rpms all started after i sank the truck