ef9

A few months ago when I replaced the AC compressor on my 92 SC300 (173k miles) the car developed a very annoying noise in the engine bay. Its very similiar to the noise that a bad alternator will make..kind of a chirping noise accompanying the pace of the engine RPM. I replaced the alternator last week so thats not it..I replaced the serpentine belt so thats not it. I even started the car with the serpentine belt off so I don't think its any of the accessories. Could it be the belt tensionor or the bearing inside it? That's all I can come up with from my searching. Someone please help..the noise is really kind of embarrassing when pulling into parking lots..my car sounds like a hooptie.

Thanks in advance.

KidPandJ

if you started the car without the serpentine belt on, and you didn't hear the noise, then it won't be the tensioner because the serpentine belt spins that. Are you auto or stick? Could be your pilot bearing if you have a stick.

FireCode

iTrader: (1)

check the idler bearing.....

ef9

It is a 5spd, BTW. Where is the idler bearing? I used a stethoscope and the noise seemed to be more pronounced around the intake manifold side of the head. Almost around where the intake cam is? I could be wrong there though.

The noise WAS still there when I started it with the belt off..would the idler bearing affect that?

KidPandJ

Does the noise stop when you depress the clutch pedal..if so then it's probably the pilot bearing which is in your transmission. The clutch rides on it when it's pressed against the flywheel. Otherwise yeah it could be your idler bearing which is in your front timing cover where the tensioner is. When i mentioned that about the noise still being there when the belt was off i thought you were asking if it was the tensioner pulley, which puts tension on your serpentine belt. The idler bearing/tensioner is what puts tension on your timing belt (inside the timing cover) sorry for the confusion. Hope this helps.

FireCode

iTrader: (1)

does the noise get quieter after turning off the AC? Just wondering cause when my idler bearing needed replacing, the Ac on made the noise louder

ef9

The noise is there and the same volume with the clutch in or out and with the AC on or off. So, what part do I need to replace? The entire tensioner or just an idler bearing? Where should I get it and how much?

Thanks!

FireCode

iTrader: (1)

start with the idler bearing.....really cheap. Do a search on here "idler bearing" there is a thread somewhere that has the part number.

VSsc400

iTrader: (1)

idler pulley.

read the whole thing

https://www.clublexus.com/forums/sho...ighlight=dayco