a lil while after getting my swap running something developed a bad squeal. ive replaced the alt idler the tensioner pulley and changed out the waterpump yesterday. after putting the pump on and firing it up it was nice and quiet but as it ran it started to squeal again. starting to wonder if the reman alt i have on it is the culprit. i went for i drive around the neighborhood yesterday and after running it some it will pretty much go away completely at idle but be awful at anything above idle. here is a video of what it sounds like.

 

How old is the tensioner itself and is there any side to side play?

 

not sure how old it is.

 

I had same issue and tried everything. Here, I needed to press on my balancer another 16th and the sound went away. It was wearing the edge of the belt also.

 

I'll check that out too. I'm gona pull the alt off and trim some of the dust cover on the back also it's mashed hard against the clamshell I'm sure that isn't helpin matters.