This is a Ford engine and I have run across this before. It's likely not a pully at all and it's coming from the Camshaft sensor drive unit called the "synchronizer". Get a long screwdriver to the base and your ear and listen to it. Don't try to change this yourself without the proper tool as it has to be timed correctly and cannot be done without the tool once it has been moved.
Tuesday, November 16th, 2010 AT 6:26 PM