Understanding Fuel Filters

The fuel filter is an important component used in all cars, trucks and other vehicles powered by a combustion gas engine. As with other filters, it's designed to catch and hold impurities. As fuel travels from your vehicle's tank to the engine, it passes through the filter where dirt, debris, sediment and other impurities are removed. Over time, however, fuel filters can fail. Below are five possible signs you may notice when your vehicle's fuel filter begins to fail.

#1) Doesn't Start on First Turn

If your vehicle doesn't start on the first turn, it could be the result of a failing fuel filter. As the fuel filter becomes clogged, fuel may struggle to enter the fuel lines and, therefore, reach the engine. And without fuel, the engine won't start. You may be able to force a small enough fuel into the lines by pumping the gas pedal, but this is only a temporary solution that doesn't solve the underlying problem.

#2) Engine Misfires

Engine misfires can be the result of a failing fuel filter. The clogged filter prevents fuel from reaching all the engine's cylinders in an even, equal amount. As a result, some cylinders may receive more fuel, whereas others receive less fuel. This problem can manifest as a misfire in which your vehicle jerks or stutters.

#3) Low Engine Power

Of course, low engine power is another possible sign of a failing fuel filter. All combustion gas engines need three things to produce power: air, fuel and spark. If your vehicle has a clogged fuel filter, the engine may fail to receive a sufficient amount of fuel. The engine may still run, but you can expect lower and less-consistent power.

#4) Check Engine Light

If your vehicle's Check Engine Light (CEL) is turned on, use a scanning tool to determine the specific fault or faults that triggered it. The CEL can activate for a number of reasons, one of which is a failing fuel filter. If your vehicle has one or more sensors to measure fuel pressure, for instance, it may trigger a CEL if the fuel filter is bad. The failing fuel filter trips the sensor, which then triggers the CEL.

#5) Low Fuel Pressure Reading

Finally, low fuel pressure can indicate a failing fuel filter. You can take your vehicle to a professional mechanic to have them pressure test the fuel system. If your vehicle's fuel pressure is lower than that specified by the automaker, your engine may struggle to get a sufficient amount of fuel, in which case you should consider replacing the fuel filter.