97 GTP eating accessory belt

I have a 97 GTP.

Recently I ended up having to replace an alternator, water pump, and the tensioner assembly. The tensioner was the last thing to get replaced. Afterwards the belt was squeeking a lot, so I changed to a nice gatorback belt and it went away.

Today I open the hood, and the accessory belt is ate up on the outside edge and is down to 5 ribs. I'm pretty sure that the new tensioner assembly is the problem, but i'm kinda curious as to exactly what... wondering if anyone has any suggestions on it?

make sure none of your pulleys are bent.....or maybe the tensioner is to loose/ or tight.

Did you get the right size serpentine drive belt? There are two sizes for the 1997 model. One is about 1/2" longer than the other. What brand tensioner did you install? Aftermarket or GM? Also, you may have misalignment with the pulleys so check that out especially on the parts replaced such as the water pump and alternator.

Gatorback Gatorback Part # 4060935 93 1/2" BELT - Matches AC Delco 6K935
Gatorback Gatorback Part # 4060930 93" BELT - Matches AC Delco 6K930

Yeah, we checked the old belt. I have the longer one. The problem didnt start until I change that tensioner assembly. It was maybe a month prior to that that I'd done the water pump.... enough time for it to seem fine for a while then start to overheat again and ruin my day. And the old belt started to squeel after i'd had the car sit and run for 10 minutes after getting everything put back together and refilled and all that good stuff.

The one I got was what they had at AutoZone. I want to think the brand was Dayco or something like that. The local Pontiac dealer here doesnt like to carry stuff like, plug wires for my car for some strange reason (figure'd theres enough of the motor out there that they might have at least one set). But if I have to go back and get a GM assembly, and wait a few days, then I guess that's what i'll have to do.

I'll get a chance to tear into it next weekend and be stumped for a while. I have another vehicle to drive if need be.

Just out of curiosity on the belt..... Why exactly are there 2 different sizes?

Sounds like you have it narrowed down to the tensioner, especially if the problem did not start until it was replaced. I recall some people having problems with AZ tensioners. Not sure if it was the Dayco brand since they change parts suppliers. The current tensioner offered is made by Dayco.

Using the GM one is probably your best bet and as an alternative the Goodyear brand tensioners work fine.

I believe the two belt sizes had something to do with different alternator pulley sizes. I use the Gatorback 93 1/2" one.

Had this on my 98 gtp. it was a very small leak from the water pump that was sitting on the pulley/belt and with every start-up more of the back of the belt came off. check your water pump for leak.