I have posted before on this issue but didn't get too much feedback, so I thought I would try again. My 1999 f150 makes a terrible whining/squealing sound while it is running. I am not thinking it is transmission related, becuase it does it in neutral/park, as well as while driving, and is related to the RPM's. I now have about 122k miles on the truck, but this squealing is driving me nuts. Someone suggested the CPS (camshaft possitioning sensor), but I didn't think that was the issue because the truck runs great, no misfires or unusual gas mileage or anything like that. Does anyone have any ideas as to what might be causing this noise? I am hoping someone can help me pin-point this blasted noise so my truck sounds like a truck. Thanks in advance guys.

Brandon.

 

I have no idea.
If it were me, and I have been in similar spots before so at one time or another it WAS me, I would get a mechanic's stethoscope and use that to dial in on the source of the noise.
Knowing exactly where it is coming from is going to be the first step to finding the cause.

A stethoscope is an invaluable tool. I had a squeak in the front end one time and could not figure out what it was. The stethoscope lead me to the exact spot on the rubber bushing at the bottom of the right front strut. Took about 30 seconds to find it.

Give it a try and let us know.

 

I was thinking that it might be the idler pulley, from what I understand that is a fairly common problematic pulley on these engines. Guess all I can do is check it out like you say and get this problem taken care of. Thanks for the input,I'll try to get it checked out this weekend and let you know how it turns out.

 

I've got a god awful squeal myself and it has to be one of the pulleys connected to the front of my engine the only problem is there are quite a few that it could be and I've already replaced half of them and tried three different brand belts.

Lower idler pulley - Replaced
Alternator - Replaced
Belt Tensioned Pulley - Replaced
Upper Idler Pulley - original
AC Compressor - original
Power Steering Pump - original
Fan Pulley - original
Crank Shaft - New Engine & New Pulley

 

Yeah I finally just put this truck on the backburner too, yesterday I brought home a new truck, so now I am all over that, as it is my first 300 inline six. I have put about 22k miles on the 4.2l and it has made this squealing since I bought it. I don't think it is anything too serious, it is just real annoying.

 

put a stethoscope on the block next to the cam position sensor and see if you hear it strong there.
I have recently come to realize that the 4.2(& 3.8) camshaft sychronizer squeals like a belt or pulley gone bad.
Thought it may be worth mentioning.....

 

Solved my Squeal. After 5000 miles of squealing, three different belts and a few extra pulleys it turned out to be dirty equipment.

I took off the belt cleaned it in the bathtub with dishwashing soap then cleaned all the pulleys with break cleaner. I've got 2000 new miles so far with no squeak. Just goes to show sometimes throwing parts at a problem is not the solution.

 

Persistence paid off! Congrats!

 

My truck still squeals.. Never could figure out why.. tried everything, but cannot seem to pin-point the noise. Used 3 cans of brake cleaner... all to no avail.. I give up, I'm just gonna drive it and turn the radio up..

 

Remove the serpentine belt and run the engine,but not for too long! This way you will know if it is a pulley causing the noise.

 

+1
I pinpointed the whining noise to power steering. I highly recommend stethoscope.