Serpentine noise I just replaced the idler pulley and new serpentine belt on wife’s 96 Grand Voyager. Idler was making a lot of noise (98K on the car). I did this following the instructions below. Now have a louder shrill that coincides with the RPM’s. It sounds if coming from the air condition compressor which has not worked in 3-4 years. Anyway I thought this would be a freewheeling pulley, any ideas? I checked the belt and it looks straight. If I spray WD 40 on the pulley (compressor) it quiets down however this last for a very short duration.

SOURCE: 96 plymouth voyager. PO113 code

First, if you have access to a scan tool, is there an IAT reading? If the IAT reading is logical then the problem is likely intermittent. If the reading is less than -30 degrees, unplug the connector. Install a jumper wire between the harness connector signal and ground circuits. The IAT temperature reading on the scan tool should be maxed out at the high end. For example it should be 280 degrees Farenheit or higher. If it is, the wiring is okay, and it may have been the connection. If it isn't install the jumper wire between the IAT signal circuit and the chassis ground.

If now the IAT reading on the scan tool is maxed out then check for an open in the IAT ground circuit. If you get no reading at all on the scan tool, it's likely that the sensor signal is open or the 5 volt reference is missing. Check using a DVOM (digital volt ohm meter) for a 5 volt reference. If it's there, then unplug the connector at the PCM and check for continuity on the IAT signal circuit between the PCM connector and the IAT connector.goodluck

SOURCE: My Serpentine belt is squealing above idle

first thing you need to do is get a new belt that belt dressing just destroyed that belt that stuff is no good then get a new belt tensioner clean all the pullys with some brake clean then install the belt tensioner and belt if its still sqealing there maybe a pully making the noise to check that when you have the belt off spin them by hand and listen to them and feel for any play in the bearings

SOURCE: sounds like belt squeal on 1994 Plymouth Voyager

this could be the result of a few things.a belt thats too tght or too lose.there could be a bearing in the altenator going bad causing some grabbing on the belt.ther also could be an air compressor clutch beginning to freeze up.I hope this helps,

SOURCE: replaced alternator on 1993 Plymouth

The tensioner is the only thing that will make a clicking sound, caused by the spring in it. But this doesn't mean that it is bad. To check pullies , remove the belt and turn them. they should spin freely. Turn them slowly also, if you feel any roughness then they are worn out. Do this to everything the belt touches, Alternator, a/c , power steering. Also the pullies should not wobble.

SOURCE: belt squealing on a 1998 plymouth grand voyager 3.3 liter motor

have u checked the dampner pulley,it may b coming apart. if it only squeaks with the a/c on then it's your a/c clutch pulley.