Hi everyone! Im a new member here but have used these forums to find the answer to numerous technical questions i have had in the past.
I have a 1989 Camaro RS and for the past 8 months i have been trying to find the cause of a mysterious squeaking occurring somewhere on the serpentine belt. I have replaced the belt tensioner pulley twice, the smog pump, the alternator, and the water pump (its a high volume pump idk if that makes a difference) without any luck. Belt dressing just makes the squeak louder and more intensive. I know for sure the squeaking is coming from one of pulleys because if i release tension on the belt tensioner assembly the squeaking goes away. Also the squeaking goes away after the car has been driven and reached an operating temperature of about 200 degrees. At startup the squeaking is very loud and makes an otherwise great car sound very poor. The only three things left that have not been replaced are the AC compressor, the power steering pump, and the harmonic balancer pulley. I'm wondering if anyone has any suggestions on how to determine the cause of the squeak (i have already listened to each component using a screwdriver to my ear and they all sound to be working fine) or if anyone else has encountered this problem and can tell me what needs to be replaced? does the belt tensioner assembly get tighter as it gets older (seems unlikely) and need to be replaced or is there a way to set the spring in the assembly to make is looser?

 

Welcome to TGO. As I understand it, the tensioner takes up slack as the belt ages/stretches. Could the belt itself be the culprit?

JamesC

 

... double check to make sure its in good condition and the right one, look for one of the smooth pulleys, or the pump its bolted to have alot of rotational friction.

 

i fixed my squeeking by taking the belt off and using a mechanic's stethloscope to listen to the bearings as i spun the accessories by hand. if i could hear the bearings grinding or squeeking while spinning it by hand, i pulled the accessory off and had it tested at advanced auto. what they do is hook it up to a belt and turn it on and if i heard that godawful squeeking i knew it was bad. it turned out to be my alternator.

i would also do a visual check to make sure everything is alligned properly (ex. make sure everything is straight).

 

the belt was fairly new when the noise started, only about two months old. A friend suggested getting a gator back type belt to adhere to the pulley better, but wouldn't that just make the noise louder as more tension seems to make the squeaking more frequent? also where would i get one of those mechanics stethoscopes?

 

I got mine at harbor freight in norfolk, virginia. If you don't have one by you u can always get it from their website, www.harborfreight.com. (lots of tools for mechanics at great prices) I'm actually about to go listen to mine! I have the same problem, brand new belt with a tensioner about 2 years old.

 

A very long screw driver will work as a stethoscopes. Just put your ear to the handle and touch the accessories one at a time.

It needs to be LONG and you must watch out for moving parts as always.

THe screw driver I use is about 2.5 or 3 feet long.

 

The majority of the time I have had problems with a squeaking belt, it has been the belt itself that was the issue. Even if an accessory pulley squeaks when you turn it by hand, sometimes it won't when the belt tension is on it. There have been times that I have thrown lots of parts at the front of an engine and been totally frustrated, only to have a relatively inexpensive new belt solve the problem.

My routine now is to always have an extra (new) serpentine belt on hand. If I get a squeak, the first thing I do is throw the new belt on and see if that eliminates the problem.