Gas gauge acting strange

uh6077 · January 20, 2007

I have a late model 99 Silverado. The gas gause has been screwy since I got the truck about 4 months ago. I fill up the tank until the gas pump clicks off. My gas gause goes way past full. I go about 80 miles before the needle hits full. When it gets close to E, the fuel light come on. I then drive another 40 miles or so before I get gas. I have a 26 gallon tank but when I fill up, after driving 40 miles on E, I only have to put in 22 gallons. That means I still have 4 gallons left. I am getting about 16 mpg. Stay with me here. If I drove for about 40 miles (around 2 gallons of gas) and still have 4 gallons left, that means the light is coming on what I have 6 gallons in the tank. 6 gallons is almost 1/4 of a tank so the light is coming on way too soon. It does another odd thing as well. Say the gauge is showing 1/2 tank. Sometimes when I shut the truck off, go into a store and then start it up again it will read 3/8 or 1/4 tank. When I shut it off an start it again it will be back to correctly reading 1/2 tank. Any guesses. I go by the odometer and not the gauge but it is bothering me. Thanks in advance.

omegafiler · January 20, 2007

It really could be the guage cluster or even the fuel pump. But those trucks have quite a few issues with the fuel pump/sending unit going out on them. Of course, that typically doesn't happen until around the 100k mile mark.

The guage on my friends 99 Tahoe would actually jump around sometimes while driving. We just replaced the pump, which is all one assembly, and never had that issue again.

hotrodtruck85 · January 20, 2007

My 2000 Silverado had the exact same problem with the additional waving from E to F. I had replaced the fuel pump/sending unit and I've had no problems. Hope this fixes your problem.