Question squealing noise when loaded and fan on.

[JfmF250]

Truck starts squealing when pulling load up hill when fan is engaged, only does this loaded and pulling grade, it is a 2005 Lariat crew cab with a 6.0 engine. Any others having this problem.

 

[DaveBen]

Your belt may be slipping due to wear of the belt, or a weak belt tensioner. Check the tension on the belt by pushing on the belt. You should not be able to deflect it more than 1/4 inch.

Dave

 

[RJDiesel]

I get the same thing, I did notice it was worse with the A/C running. My belt looks to be in good condition but I will need to do the tension test Daveben stated.

 

[BIG JOE]

How's the Boost pressure when the squealing is going on ??