1998 Gran Caravan, 3.3L: Started getting a loud noise on something attached to one of the belts. Can't tell if its the alt bearings, the water pump, or some other device (AC compressor?). Hard to describe the noise, and no other symptoms present - Has anyone had this problem?

 

Belt tensioner. Chirpy/squeaky noise? Common problem. My first Caravan was a 96 3.3 and I learned about the belt tensioner. The bearing dries out and starts with little squeaks then loud chirps. Better change it. That would be my guess.

 

What you want to do is go down to harbor freight(or wherever sells cheap tools near you) and get a mechanic's stethoscope, it might cost like $10-15. That will help you narrow it down to exactly what is making the noise. I guarantee you'll get enough use out of it to be worth the price.

 

The belt tensioner is a likely suspect and fairly cheap to replace. I replaced mine when I did my alternator as I found it suspiciously squeaky after I had the belt off. I thought it would be easiest to replace it right away while everything was already apart. Could be bearings in the alternator or water pump as well. Another potential source is the power steering pump, though you would hear increased noise when turning the wheel under load, i.e. when you turn the wheels while stopped/idling. Good luck.

 

Thanks for all for the advise - Tried using a piece of heater hose as a stethoscope, and the noise is louder from the tensioner. Is it hard to replace for someone with a modest skill (and tool) set?

 

I have never actually replaced one myself but I would not be afraid to try. I would go to Auto Zone or someplace where you can buy one and look at it and see how easy it looks to install.

 

Best way to figure it out, is to take some tools to a walk in wrecking yard(if there is one nearby). Try taking one off of a van, It will help you gain knowledge without the risk of disabling your own vehicle, and when you go to change your own, you'll have the experience.

 

Well, had a chance to do more stuff this weekend. After taking off the belt, it looks like all the pulleys were rotating pretty well EXCEPT the AC compressor. Very rough spinning, and feels like the bearings are shot. Replacement costs for this item are pretty high, and I think only qualified folks can replace the refridgerant. Anyone know any elegant (cheap) solutions? In this area of the country, I rarely use the AC.

 

Does the AC have it's own seperate belt on the 3.3? I know it does on the 3.0. If it does, just remove the belt. If it shares it's belt with everything else, then you could get a non-AC belt.

 

3.3L just has 1 belt
You should be able to replace the A/C Clutch assy.
You might be able to just replace the bearing if you take the clutch apart and go to a bearing supply store.
You don't have to discharge the refrigerant to do this!