I decided to put on a new serpentine belt and i notciced it would randomly squeal. It did not squeal until i tried the new belt. Is there a bolt to loosen or tighten to check the tension on the belt? I put the old belt back on to narrow down the suspects. Old belt squealed too. As of now the old belt is on, tomorrow I will put the new belt back on and try changing the tensioner pulley (off a series II 3.8L from my mom'* intrigue) , just the pulley not the large spring that gives the tensioner bracket the tension. (We broke part of the coolant passage when we did her LIM replacement).

It only squeals when the car is moving, for whatever reason, it rarely squeals while idling or sitting in the driveway. DRY conditions or wet, makes no difference. It would be easy to find the pulley that is making the belt squeal, but I am having a hard time to re-create the problem. The only time i can consistently make it squeal is slowing down (from any speed above 30) before the RPMS reach 1,000. Average RPM would be 1,200 while the squeal takes place.

I'm not sure that I totally understand. Do you believe it to be a pulley that is making the noise, or do you think that the belt is slipping...or just noisy? If it is the belt, some have had success with using a gatorback belt to quiet things down.

On the L36, I think you only have the one pulley on the tensioner. Other possibilities are the alternator (rear bearings can dry out) and water pump. The belt tensioner is the only adjustment for the tension put on the belt.

There are marks on the tensioner to show you if the belt is too loose or the tensioner is out of spec. Is that what you are looking for?

Well the problem is that I can't recreate the problem while it is idling, so I can not figure out if it is the belt slipping or maybe one of the pulleys, such as the power steering or waterpump, seizing up. It only squeals for 1-2 seconds at a time, but only while slightly in motion. It never squeals while accelerating, only when braking and slowing down near 20 mph, or 1200 rpms.

Does anyone have any links or more information to the pulleys(alternator and Waterpump) seizing up?
Is there any way to grease the alternator to check?
How about a picture of someone elses tensioner pulley?

I am hoping I was a little more clear this time.
If not, i apologize, it'* very hard to explain because it'* hard to recreate the problem.
If you ask me questions, i will be glad to try to answer yours.

Thanks

Can it be recreated in park by raising and lowering the engine speed to around the same rpm? If it is just while braking, might it be something with the brakes, rather than the engine?

Other than that...remove the belt and give everything in the belt path a spin. Anything bind, or not seem right?

The noise was definitely a belt squeal. It can not be recreated in park with changing the engine speed. It is very random though only under lower RPMs. I put a new belt on, and ilder pulley, not idler spring. I will report back.

I changed the tensioner pulley and put a new belt on, it still squeaks, but not as often. Could it possibly be the air conditioning compressor? It is starting to shave off metal off of the clutch... but do they squeal when they go bad?

Is there any change in the sound depending on whether or not the A/C is turned on?

If the air conditioning is on, it doesn't squeal.

I thought that the compressor might make the belt run a little bit faster;thus stopping the squeal but it could be because the compressor is engaged.

You can't get the same noise if the AC is on? That would probably be an AC clutch..combined with the metal shavings..I'd be doing that compressor pretty soon before it locks up and possibly leaves you stranded