Symptoms of a dirty fuel filter include losing power while driving uphill, problems starting the car, stalling, grinding noises in the engine, the smell of gas fumes and an engine that misfires frequently. An engine that hesitates when the accelerator is depressed can also indicate a dirty fuel filter, especially when this occurs at slow speeds.
The job of the fuel filter is to keep debris out of the gasoline in a car. When a fuel filter becomes dirty or clogged with debris, the flow of gasoline through the car is impeded, and the fuel pump ends up working harder.
Hesitations in the engine are a direct result of the gasoline flow being impeded. This results in abnormal combustion and reduces the engine's power, resulting in the hesitations during acceleration. Stalling occurs when the flow of fuel through the engine is extremely restricted. Problems with starting can also be due to a dirty fuel filter, since an engine requires a certain amount of gas to start the internal combustion process.
A dirty fuel filter can damage the fuel pump if it is not replaced. Replacing a fuel filter is typically a fairly easy task. Fuel filters should be changed at least once a year.