Squealing drive belt. Tried Everything!
I've got a 96 Dakota with the 3.9 V6.
I'd been having minor problems with the belt squealing. I replaced the tensioner, and belt a year and a half ago, and that helped for a while.
Then it started back. At first just when it was cold then it would stop. Not it sounds like someone is slaughtering a hog under my hood.
I've replaced the belt, and that didn't help any. I thought a pulley or bearing was going bad on something. I called an old timer mechanic, and he came over and checked it out, and said the tensioner was OK, then he put a little brake fluid on a rag, and held it against the belt. Instant silence as soon as he did it. That made me think the there were no problems with any of the pulley's, but the noise came back after just a few miles.
I called him again, and asked if he was sure the tensioner couldn't be bad, and he keeps telling me no, that its fine. It does seem to keep the belt tight, but other than replacing it, and the belt I don't have a clue what to do.