I've looked around every site I can think of and still have no concrete answer to my problem. Passenger side of engine, when starting, and noticeably louder now that it is cold, a "fluttering squeak" that goes away once the RPM increases, but can be heard each time the engine is started. I've had multiple guesses but no fix. The tech at our local Ford shop got under the truck with his stethoscope and listened around the exhaust manifold. He thinks it is "wafers" used as exhaust gaskets that have shrunk just enough to flutter back and forth until they expand with the heat. Sounds hokey to me but, any other ideas?