Originally Posted by MDTAHOE

Put your ear to the fuel filler, does it sound like it is coming from inside the tank? I have seen many times on GM trucks where the fuel filter becomes very restricted thus causing the fuel pump to work to hard which makes it louder. Sometimes if caught soon enough filter replacement will quite down the pump. If not caught soon enough pump failure will eventually happen.
On a side note sugar will not dissolve in gas. All that needs to happen is removal from the tank. Because the pump has a "sock" on the bottom the sugar can never get into the pump or injectors.