Over the summer my 2001 F150(5.4L) seemed to have a squeal at high RPM's(3000 or more).
It seemed to affect engine RPM a bit(slight fluctuation) and sounded almost like a belt slipping.It seemed that in order for me to get the sound to go away I had to back off of the throttle.
Most of the time it happened when pulling the trailer(3rd gear) but has also occurred under some very hard acceleration testing.just before it shifts to o/d.
The truck also hesitates to go anywhere in Drive after backing up when cold.You back up ,stop, throw it into D and it will sit there and do nothing,step on the gas a bit more and it starts to move,although it seems sluggish(does not make any noises).Only does this when cold.
The truck runs fine besides and only has 20,000kms on it.
I posted this on FlatRateTech and the guys there seem to think it is tranny related,mainly the pump starving itself.
So has anybody here had any similar issues or any ideas about this problem??
What kind of damage could I be doing to the tranny when this occurs??
I had a 98 F150 that lost a tranny,a 2000 F150 that blew a plug(both at low mileage).
I think that if this one has problems my faith in Ford will be completely gone!!

 

This is what they said on FlatRateTech


"You may want to check the fluid level for the trans, low fluid can cause exactly what your describing, delayed engagements, the sound your hearing could be the front pump starving for fluid not being able to keep up because of low fluid level."
--------------------
Mike Mclaughlin
Master Certified Service Manager
FRT Staff
BON Staff Writer


Yes I've checked the tranny fluid level,and it's OK(also does not smell or look discolored).

 

could be a bad bearing in a belt driven item as well. Have someone rev it for you with the truck in park.

 

You may wanna look at the serpentine belt for the squeal, especially if there is a chip or shift kit in the trans.