I have a 1997 Nissan Maxima with 111,114 miles on it, mostly highway miles. Every morning when I start my car it will squeal real loud until the engine warms up. Once the engine is warm it quits making the noise for the rest of the day until it sets over night again.
Checked out the condition of the belt and it was fine. Noticed that this 3.0L engine had 2 serpentine belts and they were both a little loose. This would be an indication of a failing auto tensioner on most cars but this engine has manual tensioners. Adjusted both belts ( should just be able to twist the belt 90 degrees and that all the play you want ). Let the vehicle set overnight and tested. No more squeal. Customer happy !! Cost of labor, $25.00