Alternator pulley squeal

[pr627]

ok guys, let me know if u have experienced this OR if u have any suggestions....

this started a few days ago. I am driving my car and after it warms up really good u start to hear this squealing noise. I stop the car and leave it running and open the hood. the noise appears to be coming from the alternator pulley. they are the stock pulleys which i believe are underdrive on the 96 Cobras. it stops when car is idling but when I revved it up around 1200 rpm or more u can hear the squealing. I sprayed a little wd-40 around the bolt that holds the pulley on and the squealing stops for awhile but later on it will start again. It has never been as loud as it was initially since I first sprayed the lubricant on.

I also thought about maybe loosining the bolt slightly and then tightning the bolt back up and here is another question....
how do u know if it was tight enough from the beginning and if not , how tight is too tight ? it appears to me when I am tightening, it only allows u to go so far even though the nut is still turning

 

[SNK BITN]

Get the torque specs on that bolt and torque it down properly. Not sure about the squeal.

 

[Cobrahandler]

make sure the tensioner is working right and keeping pressure on the belt system.
also, if the belt has been changed from the factory belt, you may have a mismatch. the groves in the pulleys and the belt must match exactly. gates and others make "replacements" that don't match exactly and they will squeel. ford put one on another ford that i own and it was a gates belt..and squealed after a few weeks. went back to a motorcraft belt and all was fine.
hope this helps.
also..make sure your alt. bearing isn't freezing up or idler pulleys aren't tight.

 

[SVT X 2]

If the belt is stock, what kind of condition is it in? You hopefully only need a new belt.

 

[love bandit2]

Its the belt tensioner. They are pieces of crap. It went on my cobra and the exact same thing happend. Last week it happened to my Dad's F150 with the 4.6L. The belt squeals like hell, and it only gets worse as time goes on. So don't waste your time with belt dressing or anything, just take it to the dealer and have it replaced.