Clean all the pulleys of with a wire brush while rotating them. Most of that junk you see is because of the spray you used, that didn't help matter's any. And the new belt has that crap on it too now. So clean the belt too.

 

You made the noobs mistake dude. You allowed the evil spirits to enter your truck through the open drain pan.....Bad joo joo!!!!

But seriously, It may be what the others are telling you or I have read that these self tensioning belts do not like belt dressings. I would wash it all off and see if once it dries if the noise goes away. The belt dressing was good on the old single belts, but not on serpentines.

If that doesn't work you can always run around the truck three times chanting the magic joo joo song, and spread sheep's blood on top of the hood. That always works for the witch doctor down the street from me.

 

omg