Every time I let off the gas while driving, a high pitched whine sort of sound comes from under the hood. Also when I turn the truck off the sound still happens. Does it like 2 or 3 times and stops. Any suggestions as to what it could be would be awesome. Thanks guys!

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Possibly a fan clutch going bad. Possibly a belt tensioner or pulley bearing. One of these items would be my guess from your description.

 

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