I have a 99 Tauras and I've been having trouble with my belt. I've replaced it 8 times in two months. This week when it popped the first time we seen the black dust like stuff that was getting burned off the belt on the radiator tank and alternator. When we replaced it, it pooped about four hours later when I went to the store. We looked at everything but we didnt see anything that it could be leaning on so we replaced it again and it popped in a few more hours. So we we cleaned off the pulleys and the idler and replaced it again and it popped later that day. It looks like it keeps rubbing against something. It keep popping on the outside end. Then when I put the belt on top of the tensioner it be even but when I start the car the belt pushes over to the end of the tensioner istead of the middle of the tensioner. It stays tight on there but a little piece of it sits at the edge. i was told maybe one of the pulleys needs to be replaced if so how do I do that and how do I found out which one needs to be replaced.

This may seem like a dumb question to you but, what do "Popping" mean? Is it coming off the pulley or breaking?

Sounds to me like the tensioner arm itself is weak and allowing the pulley to cock slightly causing the belt to come off. I would trplace the tensioner assembly and the idler pulley. The tensioner assembly it the highest cost. Not sure of cost. The tensioner assembly is held in place by one bolt. It is easil replaced if you take your time and look before you jump in to the repair.

This may seem like a dumb question to you but, what do "Popping" mean? Is it coming off the pulley or breaking?

A piece of the outside of the belt looks as if it rubs against something and it split off from the rest of the belt and tears into 1 long piece and then it get stuck around some of the pulleys causing my car to stop

Are you absolutely sure that the belt is properly seated on all pulleys? Sometimes it may look as if it's on correct, but will actually be off by one rib. The outer edge of many of the pulleys could certainly slice through the belt as you describe.

Did this start to occur after a routine belt replacement, or did a similar thing happen that caused you to change the belt, and this has been happening ever since? If the former, then I would certainly suspect that the new belts are not being installed correctly. If the latter, then you probably have a pulley alignment issue.

-Rod