1995 Oldsmobile Achieva Oil Pressure

Howdy! First, my oil pressure sending unit may be bad. The gauge fluctuates a lot. When I step on the gas, the neddle pegs all the way to the right. It has at times though in idle, gone down all the way to the left!

I would suspect only that but, cold starting, I hear metal on metal sounds coming from what I can tell to be the top left part of the engine. (Facing the engine) It seems once the car warms to NOT, the sounds greatly diminsh, which kind of leads me to believe bad circulation for the oil!

I flushed the engine twice with the same results. Any help would be great. Thanks.