Hello guys I have F250 LD since i bough it has been doing this chirpling sound coming from the serpentine belt and the pulley area but when the truck has been working for 15 - 20 min it goes away


This is apart from the from the problem before I think the fan clutch is broken because when I start the truck I can hear the fan going at the same speed of the engine is that normal ? even when the truck is cold

 

On a cold start-up, the fan will spin fast for a bit until the clutch fluid warms a little and disperses in the clutch.
As for the chirping, it could be the belt itself, or possible an idler pulley bearing. I would remove the belt and turn the pulleys by hand and see if any make noise or feel like they grinding from a bad bearing.
If the belt isn't fairly new, I would start there with a new name brand belt such as Gates, Goodyear Gatorback or Motorcraft.

 

thank for fast reply LXman1 good to know about the fan ....

on the other hand i recently replace the belt with DAYCO brand I will take it off and spin 1 by 1 in case of I can the grinding do use grease or replace the pulleys ?

 

ok so looks like the problem is coming from the pulleys that are not serving any function but to tight the serpentine belt so other pulleys that serve a function like the alternator or like the A/c work (im not sure what the name of that pulley is )

figure the problem goes away by spraying a little WD 40 inside of it not over the belt part will work for 1 day when it dries up noise is up again .....


so my question is does this pulley has any rolling mechanism...? is it replaceable or do i have to replace the whole pulley .....?

how do i fix this ? thanks in advance