fan belt squeeking

My fan belt was sqeeling just like a mouse for a second when I press the gass so I bought another one and it is doing the same thing. Is there a belt tentioner adjustment I am missing or what. has anyone ever had this problem?
Thanks
 
they dont call it a fan belt as it doesnt turn the fan.. surpentine belt . the tensioner doesnt adjust.. its just a spring arm.. go and get yourself a new tensioner.. underdrive pullys love to squeek
 
try the idler pulley,they are like 12 bucks at autozone,they tend to make noise when they age,the bearing actually siezed up on mine and back the bolt off causing it too fly off haha.