The fuel filter is the filter that keeps out any debris and rust from the fuel. The filter is an important part to the modern engine fuel system. It is usually made out of filter paper. Also if a filter is not replaced it may cause clogging and restriction in fuel flow, leading to poor performance as well as engine trouble.
Filter Damage and water sensorWater can be harmful to diesel engines, causing rust and corrosion to the fuel system. Diesel acts like a lubricant for the moving parts, but if the water enters the components it can cause the moving parts to make contact and wear faster.
The diesel fuel contains a water sensor that gives a warning to the ECU if the water reaches a certain level. Water can cause overheating and wear to the moving parts, and need to be drained from the filter.
Common issues with a bad fuel filterA bad filter can result in poor engine performance, difficulty starting the car, and decrease in acceleration.