Most people know about changing oil, spark plugs, and ignition coils as maintenance items to improve or maintain good fuel economy. One maintenance item that is often overlooked is the fuel filter. As the name implies the fuel filter filters sediment and other crud that builds up in the bottom of your gas tank and the tanks at your local gas station. If there was no fuel filter in place, that sediment would travel to your fuel injectors and clog them causing misfires. Like the other various types of filters in your car, fuel filters have a service life and must be changed at certain mileage intervals. Once a fuel filter is worn it clogs up and forces the fuel pump to work harder to maintain proper fuel pressure. This will wear out the fuel pump and eventually damage it. The lower fuel pressure will also make the computer command the injectors to stay open longer to compensate for the lower pressure wasting fuel.
Why Fuel Filters don’t get changed often
Fuel filters used to be easily accessible in older cars from the 80’s, and 90’s, held in with plastic clips or clamps along the fuel lines under the car. They were very easy to change. As modern cars made more power and required higher fuel pressures the fuel filter designs changed and now use special metal fittings to screw metal fuel lines into the fuel filters. This made them much harder to change as New York cars deal with a lot of road salt in the winters, which causes corrosion that rusts the steel line to the filter. Normally a gas torch would be used to separate rusty bolts, but you can’t use that because of the fuel in the lines. So the solution is to cut the steel fuel line and replace part of the rusty line with new fittings to screw in a new fuel filter. This requires experience, can be time consuming, and adds parts costs to the repair. Even newer cars from Toyota, Honda, and Chevrolet made in the last 10 years now have their fuel filters built into the car’s fuel pump assembly inside the gas tank which may require removing the gas tank if there is no fuel pump service panel. Due to these added costs many people decline having their fuel filter serviced until there is a problem.
Why changing your fuel filter is important
Symptoms of a clogged fuel filter can manifest as hard starting, low engine power, loud fuel pump, poor idle, and terrible gas mileage. Once we diagnose and change the fuel filter our customers remark that their fuel economy has gone way up. Especially during highway driving where the engine will benefit from steady constant fuel pressure. As stated before, a clogged fuel filter can lower fuel pressure causing your injectors to not discharge the exact amount of atomized fuel. Then the oxygen sensor will detect that there isn’t the right amount of fuel burned. The computer will compensate by commanding your injectors to stay open longer to compensate for the inadequate fuel pressure. This causes your engine to burn more fuel and reduces your fuel economy. Changing your fuel filter also greatly extends the life of the fuel pump as it won’t have to struggle against a clogged filter burning itself up in the process. It is one of those maintenance items that usually gets skipped due to lack of awareness of level of difficulty to service due to the added labor and material cost, but definitely worth changing if you plan on keeping your car for a long time.
