The fact that the sound changed when you messed with the tensioner is a pretty good clue. Just because the noise came back doesn't rule it out as the source. I've never heard a serpentine belt squeal like the old v-belts. I'm not saying they can't ... I've just never heard one.

EDIT: Yes, the fan turns with the motor off ... fluid drive.

 

If you got a drop of coolant on your serpentine it will squeal, I replaced my water pump a year ago when I did timing chain, got coolant on it, ended up having to replace it. Belt dressing will only go so far, replace the belt, and while your at it, check spring load in your tensioner.

 

im gonna replace my belt and see how it sounds then i will do the tensioner and the pulley. the water pump and alternator are about a year old, its a 94 5.2 with 60,000 miles it was grampas truck so its in great condition and want to keep it that way. after the squeak i think i might try and do the plenum gasket i have read every post about it. .thanks john

 

Don't tear into the engine if you don't need to. Plenum gasket replacement isn't something you do as "preventive" maintenance.

 

i dont think it needs to be done yet but i sure wouldnt want to have a chance of my motor blowing up becuase of it, im undecided on wether to do it yet or not thanks john

 

Relax ... your motor's not going to blow up because you didn't change the plenum gasket. IF it starts leaking (badly) you'll notice a drastic loss of fuel mileage, excess oil consumption and quite a bit of pinging. I've got over 95,000 miles of hard driving on mine ... original gasket.