Fuel filter diesel and gasoline for different automobiles
Your Fuel filter worn out? » Read more about common malfunctions • Repair • Replacement manual
So the fuel is always clean in your car
Quality and purity of diesel or petrol can vary considerably. Several causes can lead to pollution of fuel. Refineries are subject to strict quality management. Yet, you never know if transporters and fuel station managers keep their systems sufficiently clean. Don't forget that every time you fill the tank, you open it to the environment. Particles can penetrate into the fuel tank when you fill it up. Fuel filters are installed in the petrol and diesel lines to prevent the residues from reaching the engine and its components.
A consequence of a lacking filter
If there is no filter in the fuel line, it is soon to be felt in a most unpleasant way, and still serious engine damage is rather unlikely. Undesired particles however clog the injection nozzles, and thus the most frequent consequence is a stuttering engine as well as considerable circulation problems. At worst, the car doesn't start at all. These symptoms are most problematic for the catalytic converter. An injector nozzle clogging and subsequently being blown clean can lead to incomplete combustion. Fuel vapours gather in the catalyst, where they sooner or later burn up. This process is very damaging for the ultra-thin platinum layer. The car will ultimately fail the exhaust inspection as a result of a damaged catalytic converter.
Location and construction of the fuel filter
The fuel filter sits at an ideal spot in the fuel line. Luxury cars even have several filters installed. A filter can often be found right behind the fuel tank, another one is in the engine bay preferably close to the injection pump. This filter is very accessible. The filter element is fixed with two hose clamps. Other cars have sturdy cartouche containing the replaceable filter cartridges. This construction is often found in diesel cars as they better withstand the high pressure of the diesel engine. In view of the tightening of exhaust regulation the filter becomes more and more relevant for the diesel engine: the exhaust cleaning additive AdBlue starts to flake at 4ᵒC causing blockage of the fuel line. To prevent this, reliable fuel filtering is especially important in diesel cars.
Replacement of a fuel filter
A fuel filter must be replaced according to maintenance schedule. The usual figures are 20.000 – 40.000 km (12.000 – 24.000 miles). A fuel filter is seldomly replaced in comparison with an air or oil filter and therefore this small and cheap maintenance step is often skipped. It is therefore important to be aware of maintenance steps especially for older cars and always maintain the intervals. This will keep you on the safe side. Filters in modern cars are installed in an accessible cartouche, which can be recognised by the in- and outgoing fuel hose. Replacement of the fuel filter is always an occasion for checking the hose. If it is moist and porous, risk of fire is imminent. A quick replacement makes the car efficient and safe again.
Prices for a fuel filter
Prices for filter elements vary considerably. The small universal filters which were common in old cars with a carburetor are nowadays hardly ever used. They are not designed to withstand the high pressure in fuel lines of today. Present-day cars are fitted with custom modules for filtering the fuel. Their price can exceed 20 euro (£18). In view of the long replacement intervals installing a high-grade fuel filter is always worthwhile.