How'd you pin point it to that pulley squealing?? I'm having the same problem and often it is the idler pulley, but this caught my eye when I searched water pump (my water pump is going out and I was gonna see if there were any tuts on here for replacing one) Is it possible that since my water pump is leaking that pulley is the cause of the squeal?
i actually just figured out its my timing belt squeeling lol