I have a 1995 F150 XLT with the 5.0L 302 and there is a squealing coming from the engine that sounds just like a belt squeal. I replaced the belt tensioner and the belt and it still squeals. It just started this winter and usually only does it when the truck warms up. Any ideas??

 

get some stop squeak from auto zone actaully i think it's belt dressing but Im not sure.... it isn't any more than $5 and it does work... my 300 strait 6 does the same thing.

 

I did that already and drove with it a few days and it made it worse. It was a mess. I had to replace the belt and scrape the dried belt conditioner off of the pulleys.

 

Alternator bearings go bad and sing like hell. Get a long straw or tube and give it a listen on certain areas.

 

I need to do the same to my truck. Has a squeal to track down...

 

Mine is doing the same thing, from best I can tell it is either the smog pump, idler or tensioner on the passenger side. Could be the alternator, but sounds lower. Hope you find the problem, as it sure can be annoying.

 

you need to get the most expensive belt you can find the one with the rib things on the back..also one time my smog pump seized and was squealing so bad i was going 100 the whole way home on the freeway cuz i just put a new smog pump that was siezing (spinning slower then the belt but still spinning?) and causing a squeal

 

Check all your accessory pulleys , sounds like something is getting ready to seiz up , could be the air pump ?? Goodyear gatorback is a good belt....Lew

 

it could be power steering pulley bearings too. mine went out a while ago and it squealed like crazy

 

I had a similar problem, only mine would squeal like a pig until it warmed up and it only happened when it was cold <40º. It ended up being the tensioner pulley for the serpentine belt. I invested in a mechanics stethescope to track down the problem.

 

Check to see if the belt has any cracks, if it does, replace it. Otherwise, take it off and spin each pully and see if one squeaks or has a high level of resistance.

 

I'd check out all the bearings in your accessories if you have taken care of the belt. If it only does it when it's warming up, that could mean that a bearing somewhere needs to warm up and, through thermal expansion of the bearing material, it stops squealing when the worn bearing expands just enough and the slop becomes less. This might be a blessing in disguise, indicating a bigger problem before it happens!

as some of the other members mentioned, check out the bearings by trying to listen to each one individually somehow.

Good luck!

 

I have a '92 F150 4.9l....When I replaced the power steering pump pulley i did not press it on quite far enough and the belt would squeal like a pig in heat. This was only a 16th of an inch or so out of alignment. The squeal was coming from the tensioner pulley. I pressed the pulley on a bit further and the squeal was gone for good. I tried belt dressing first but that only made a big a$$ mess.

 

I like Goodyear Gatorback and Dayco Polycog belts.

A mechanices stethoscope may be your best friend for this. I have this one and its not expensive.

Stay away from belt dressings.

Automotive Stethoscope - JCWhitney

 

Well I went to the local salvage yard on the weekend and found me a smog pump, and changed it out, but the squealing is still there. Well even though the pump wasn't the squealer, it was rattling inside pretty good. Guess I will work my way up through the idlers and save the alternator for last. Just to try to save a few bucks, is it possible just to change out the bearing in an idler? Has anyone tried it?