I have 2000 Chevy Silverado 1/2 ton single cab pick-up with over 100,000 miles(v6 auto trans.). Recently the gas gauge goes nuts when the tank gets below half. I recently had the fuel filter changed but still no relief. Any thoughts as to what might be causing this?
It’s probably the sending unit which is part of the fuel pump assembly. My 2000 Blazer’s fuel gauge has been doing the same for a year now. You might want to try a bottle or two of Chevron Techron to clean the the sending unit, but it didn’t help my truck. Unless you want to change the fuel pump ($$$), I suggest filling up the gas tank each time and tracking the mileage between fill ups.
Sounds like a bad fuel sender to me. This part is INSIDE the fuel tank and probably costly to replace, but you could ask a mechanic for an estimate. Or you could ignore it.
I agree about the sending unit and also trying the Techron for a couple fill ups. It may help solve a bad connection problem. If not, then the more expensive new replacement is needed.