Mine was fixed after i changed the pulley

 

As dbaldwin pointed out, the parts alone have a large cost. It's worth inspecting, but I've yet to replace a tensioner on a 3800 (OK, I lie, I replaced one on a '97 Grand Prix because the cast aluminum elbow sheared, I used a junk yard replacement). But I've replaced a couple pulleys.

 

It was just my $0.02. When i just changed the pulley on my 3.4 la1, it tried to eat a hole in my timing cover. Course, doubt thatll happen on a 3.8

 

I wish I would have read this thread a week or so ago. I was getting the same squeak described here. My squeak would also go away when I applied belt dressing but come back quickly. It also seemed to go away (or lessen) when the engine was fully heated. I wondered if it was that pulley and assumed replacing it would mean replacing the entire unit (not just the pulley). I hesitated because it seemed like a big job. Yesterday, I was heading down the expressway about 60 miles from home. Power steering goes out and the battery light comes on. I thought "I bet the serpentine belt just broke". Sure enough the temp started to rise. I pulled over and stopped the engine. Lifted the hood and there's the broken belt lying on top the alternator. I reached down and tried to move the pulley and it wouldn't budge. Had it towed to a local shop where the guy replaced the pulley and put a new belt on. Cost me $168 altogether. If I'd have looked here, I'd have seen it was just the pulley and could have easily replaced it myself and wouldn't have needed a belt had I did it before the pulley seized completely.

 

I have a squeeking yet again, and it seems to have gotten louder as I replaced my belt so i dunno what it is. I heard u would place a screw driver on it and see where the squeel is but i dunno, anyone remember how to pin point it?

And also anyone have a diagram for a 5.3 pulleys? lol I cant tell which ones to replace.

 

Looks like the one circled

 

Dont try a screw driver thats a horrible idea to put on a belt while its moving. That only works for like intake noises and alternator noises and that sort of stuff. Try this its how i always figure out this sort of stuff: buy a can of brake clean and spray it on the belt. If the squeak goes away its probably the belt. If not then take off the belt and spin all the pulleys. If you hear a squeak off of one of the pullys its that pulley and it needs to be changed.