Why is the fuel gauge display abnormal in a car?

[WalkerLee]

Here are the reasons why the fuel gauge display in a car is abnormal: Fuel gauge pointer moves irregularly: This usually manifests as the fuel gauge pointer dropping slowly in the first half of the gauge, but once it exceeds the middle mark, the pointer drops rapidly. However, the irregular movement of the fuel gauge pointer cannot be considered a fault. This is related to the design of the fuel pump used to reflect the fuel level, which cannot uniformly reflect gasoline consumption. Achieving such uniform changes is difficult, and it cannot be altered through repairs or part replacements. Fuel gauge suddenly drops to zero: The fuel gauge's indication depends on the fuel level sensor. When this situation occurs, it indicates an issue with the vehicle's fuel level sensor. It is likely that the fuel level sensor has become contaminated and was not cleaned in time. Gasoline contains many impurities, and since the fuel level sensor is constantly immersed in it, over time it becomes polluted, directly affecting the accuracy of the indication. Fuel gauge reading rises: This situation occurs because the linkage between the fuel level sensor and the float gets stuck, preventing the float from moving up and down normally. As a result, the fuel level sensor does not change, causing the fuel gauge pointer to remain fixed at a certain position.

[OMartin]

There are several possible reasons for abnormal fuel gauge readings in a car. I often encounter this situation, with the most common cause being aging or stuck float sensors in the fuel tank, leading to inaccurate fuel level displays. The sensors are in long-term contact with gasoline, and internal components may wear out, rust, or stick together, especially in older vehicles. Another factor could be wiring issues, such as loose, corroded, or short-circuited wire connections, preventing signals from being correctly transmitted to the dashboard. Occasionally, the gauge itself may malfunction and provide incorrect fuel readings, which is less common but has happened. Additionally, impurities in the fuel system or abnormal fuel pump operation can also interfere with measurements. For self-inspection, you can first try filling the tank to see if the gauge returns to normal; if not, take it to a professional shop for diagnosis using specialized tools, as an inaccurate fuel gauge can lead to misjudging fuel levels on highways or even stranding you on the road. It’s recommended to clean the fuel tank every six months to prevent such issues.