Fuel filters remove impurities in the fuel prior to it entering the injectors and, ultimately, the engine. Improperly filtered diesel fuel poses the risk of clogging the injectors, which can lead to poor performance and eventual injector failure. Additionally, as fuel filters become clogged, the pumps that deliver fuel from the tank to the rest of the system are forced to work harder, thus causing excess wear and tear.
A clogged diesel fuel filter may cause the vehicle to "sputter" or cut in and out at high speeds. If the filter is not allowing fuel to flow through it at the proper rate, the engine will not be able to receive enough fuel, and the vehicle will sputter while moving down the road. This characteristic may be most obvious while trying to accelerate.
The pumps that deliver fuel to the injectors and allow diesel engines to begin their starting sequence cannot deliver an adequate amount of fuel if the filter is badly contaminated or clogged. Without enough fuel, the vehicle simply will not start.
Vehicle Shutting Off
While sputtering may occur if the fuel filter is clogged, once the filter is able to purify and deliver even less fuel to the diesel motor, the vehicle may completely shut off. Diesel motors which do not receive enough fuel can shut off at any time while idling or accelerating. Without adequate fuel, the firing sequence in the motor will not occur. Losing power, while driving, can create a dangerous situation.