Chrysler Repair: loud whistle noise: water pump replaced, jeep cherokee, belt tension

Question
QUESTION: i just replaced my water pump in my 97 jeep cherokee and when i started it back up it started squeeling really loud and the check engine light came on. any idea of what it could be?

ANSWER: Hi Heather,
I would suspect that the drive belt for the water pump is slipping and if that belt also drives the generator and is slipping, then that might be the cause of the light coming on. I don't claim expertise in Jeep motors so this is based upon my general knowledge of the cause of "squeeling". The belt was involved in the water pump exchange so this is a logical place to begin. You may need to adjust the belt tension or if the belt is glazed to replace it. If a shop did the replacement they should take responsibility for investigating this noise.
Roland

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QUESTION: thank you for the last answer as it was the belt. now the squeeling stopped but now there's smoke coming from the belt tensioner pulley and it gets really hot really fast and you can see it melting the belt a bit. any idea on this one?

Answer
Wow, Heather,
It sounds to me like it is either too tight now or that the new pump or one of the other devices that is driven by the same belt (or the new water pump itself) is binding up due to a faulty bearing which is causing too much drag on the belt system. I think they need to remove the belt and figure out which device is dragging, or perhaps the belt is just worn out/glazed and slipping or ? Clearly this isn't right but I can't tell you exactly why without being there myself.
Roland