Fuel filter
The fuel filter is of great importance for the longevity of the injection system, so do not forget to replace it regularly.
For most cars, filters cost less than PLN 50, and replacing them is so easy that you can do it yourself.
The injection unit is a precision system, so the fuel must be filtered very carefully, especially in modern diesel engines (very high injection pressure) and gasoline engines with direct injection. There is nothing to save on filters, since the savings will be small, and the troubles can be big. 
Not only mileage
The mileage after which the fuel filter is replaced is very different and ranges from 30 to 120 thousand. km. However, you should not get hung up on the upper limit, and if after several years of operation the car does not have such mileage, the filter should still be replaced.
In diesel engines, it is advisable to replace them before each winter season, even if this is not related to mileage.
The fuel filter is in every car, but it is not always visible. It can be placed deep in the engine bay or in the chassis and has an additional cover to keep out dirt. It can also be placed directly in the fuel tank on the fuel pump.
In passenger cars, the fuel filter is usually a metal can that can be completely replaced. This applies to all petrol filters and, in increasing numbers, also to diesel engines, especially the latest ones. Old diesel engines still have filters in which 
the paper cartridge itself is replaced, and the replacement cost is the lowest.
you can yourself
In most cases, changing the filter is very easy. It is enough to unscrew the two hose clamps, remove the old filter and install a new one. Sometimes the problem can be lack of space or rusty connections. Quite often, the filter is connected to a rigid fuel line with a nut, and then, if it has not been unscrewed for a long time, there may be problems with unscrewing it.
In order not to damage the nut, it is necessary to have a special wrench, like the one used for brake lines. However, when the filter is in the tank, we do not recommend replacing it yourself, since for this purpose you will probably need special keys, which you should not buy for just one replacement.
After changing the filter in gasoline engines with an electric fuel pump (which is found in all injection engines), turn the key to the ignition position several times, but without starting the engine, so that the pump fills the entire system with fuel at the correct pressure.
In a diesel engine, before starting, you need to pump fuel with a hand pump in order to bleed the system. The pump is a rubber ball on wires or a button in the filter housing. But not all diesels need to be pumped. Some of them are self-ventilated, you just need to turn the starter longer.
Prices for selected fuel filters (replacements)
Make and model | Filter prices (PLN) |
BMW 520i (E34) from cheap online | 28-120 |
Citroen Xara 2.0HDi | 42 – 65 |
Daewoo Lanos 1.4i | 26 – 32 |
Honda Accord '97 1.8i | 39 – 75 |
Mercedes E200D | 13 – 35 |
Nissan Almera 1.5 dSi | 85 – 106 |
Vauxhall Astra F 1.6 16V | 26 – 64 |
Renault Megane II 1.9 dCi | 25 – 45 |
Skoda Octavia 1.9 TDI | 62 – 160 |
Volkswagen Golf 1.4i | 28 – 40 |
