I don't know where mine is coming from, replaced the tensioner in case that was the problem. Sounds like more of an internal rubbing if that makes sense.. maybe it is the IP bracket.. or maybe it's the water pump? How does the WP sound when starting to fail?
Take a 3' bit of hose stick one end in your ear and stick the other end around the pulleys you think are making noise. You'll know what is is pretty quick.
Also look for metal shavings. My cam sprocket rubs on the shield and makes shavings.
Will give it a shot. Thanks.