Cadillac Repair: 2002 Cadillac Devillle GasGage, fuel sending unit, plastic pan

Question
My gas gage just recently starting malfunctioning. It will go to full and look as though I have a full tank of gas then it will drop back down to look as though there's heartly any gas.  I can just have put gas in the tank and it will at first be at the right amount then as the start to drive it will start to go up and down. Please help me to understand what's going on. thanks.

Answer
There is a plastic pan with small holes in it which is called a baffle. Sometimes this baffle comes loose and keeps sliding around in the gas tank hitting the fuel sending unit causing an erractic fuel reading. Pull the gas tanjk and see if the baffle is loose by removing the fuel sending unit and using a FLASHLIGHT to see if the baffle is loose. If it is. replace the gas tank.

If it is NOT loose, Replace the fuel sending unit.