I own a 92 auto transmission medalist edition 4runner. My engine has started squealing in the last 3 weeks I have owned the truck. It happens mainly when the engine is cold. I have often noticed it is worse when it is hot out so I am thinking it may have something to do with the AC or serpentine belt, but it has been getting awfully loud. It usually goes away in higher gears but has been happening more frequently and in higher gears. I was wondering if anyone hear has any experience with this type of problem. What would the worst case scenario be and what would the cost of the new part and labor. I am kind of worried it may be the serpentine belt or something to do with the tranny. Thanks for the help.