What is "normal" for your car? On mine, the fuel gauge stays on full for about the first 150 miles, then drops very quickly during the next 150 miles. This is typical for this model and there is no fix for it. It is even worse if I stand there and pack more and more gas into it. I can get 22 gallons into the 18-gallon tank. There is always a large pocket of air in the top of the tank to create a crush zone in the event of an impact. Some of that air will work its way out and allow you to stuff more and more gas in, if you are willing to take the time. The gauge will continue to read "full" until all that extra gas is used up.
Even when you do not pack the tank over-full, it is totally acceptable for the gauge to not start dropping right away. The exception would be if the float for the level sensor is hanging up on something. There are two clues to look for. The first is the problem started to occur shortly after some repair was done, such as replacing the in-tank fuel pump. It is not uncommon for the float to get caught during reassembly. The second clue is if the float is getting stuck, when it does finally become unstuck, the gauge will instantly drop from "full" to the correct reading. If you see the gauge at "full" one minute, and a minute later it's at "half", the float was sticking. If the gauge reading drops at a steady rate, its working correctly, even though it might take a few miles before it starts dropping.
Tuesday, February 14th, 2017 AT 5:46 PM