Why does the fuel gauge show no fuel when there is fuel in the tank?
2 Answers
The reason is a malfunction of the fuel sensor. Inaccurate fuel gauge readings can occur in the following situations: 1. The fuel gauge suddenly drops to zero: This is usually due to contamination of the fuel level sensor, which needs to be cleaned promptly. Gasoline contains many impurities, and the fuel level sensor, being constantly immersed in it, can become contaminated over time, directly affecting the accuracy of the readings. 2. The fuel gauge reading rises: The linkage between the fuel level sensor and the float gets stuck, preventing the float from moving up and down normally, which causes the sensor to remain unchanged, thus freezing the fuel gauge needle at a certain position.
I've seen this situation quite a few times, mainly due to issues with the fuel float or sensor in the tank. If the float gets stuck by sludge, it can't move—even though the fuel is sloshing around inside, the float remains stuck at the bottom, causing the dashboard to show no fuel. Also, nowadays, fuel level sensors rely on resistance changes to transmit data, and over time, they can develop poor contact, especially in older cars where the wiring connectors loosen from constant jostling. Additionally, those small motors behind the dashboard are prone to failure, causing the needle to get stuck at zero. Last time I encountered this, I had to replace the sensor on the fuel pump assembly—when we opened the tank, we found the float completely stuck by debris. If you're handy, you can remove the tank cover under the rear seat for a preliminary check, but remember not to use any open flames near the fuel tank.
