Changing the fuel filter in cars yourself - learn how to change the fuel filter in diesel engines.

The fuel filter element is located in various parts of the vehicle. Therefore, you do not always have easy access to it. However, replacing the fuel filter is fairly easy in most cases. When does the difficulty level increase? The older the car, the more difficult this task is. How to replace the fuel filter in a car? Read our guide!

Fuel filter - where is it in the car?

You need to know where this item is if you are going to replace it. This is where the stairs come in handy, because usually this element can be hidden:

• in the engine compartment;
• in the fuel tank;
• along fuel lines;
• under the car.

If you have already found it, now you can move on to replacing the filter. What are the different stages? Read more!

How to replace the fuel filter in a car?

The method for replacing the fuel filter depends on where it is located. In older cars (for example, the VAG concern), the fuel filter was often placed next to the McPherson strut cup. Therefore, for these models it is necessary:

• unscrew the top cover;
• remove the used filter;
• fill the tank with fuel;
• collect the item back. 

However, if the filter is located along the wires under the car, you must first clamp them. This will stop the fuel supply when the filter is removed. The next steps are the same.

When should you not replace the fuel filter yourself?

This is a situation that requires you to transcend your abilities. Sometimes it happens that replacing the fuel filter forces it to be removed from the tank. Firstly, it is quite dangerous (especially when working with gasoline). Secondly, it requires the use of special tools. Thirdly, in the absence of a channel, it may not be possible to change a contaminated element if it is under the car. Then it will be better if you go to the workshop.

What does replacing the fuel filter in the engine do?

For some people, this topic is quite controversial, because they don’t change the filter in the car in principle ... never. Because of this, they do not experience any special problems with the operation of the engine. However, it should be recognized that modern power units (especially diesel ones) are very sensitive to fuel quality. Pump injectors and common rail systems need very clean fuel due to the small orifices in the injectors. It is necessary to perform several injections in one working cycle. Even slight contamination can damage these sensitive devices. Therefore, the replacement of the fuel filter is mandatory. 

How often do you need to change the fuel filter in your car?

In engines requiring very clean fuel (such as the diesel units mentioned above), it is recommended to change the fuel filter at every or every second oil change interval. This may mean a run of 20-30 thousand kilometers. Others do it every 3 oil changes. There are still drivers who stick to the 100 km limit. However, we do not recommend copying the habits of those car users who do not change fuel filters at all.

Fuel Filter Replacement - Gasoline

In gasoline engines, replacing the fuel filter does not require bleeding the system. Usually all you need is:

• dismantling the old element;
• installation of a new filter;
• by turning the key to the ignition position several times. 

Of course, you cannot turn the key to start the engine. First let the pump pressurize the system several times. Only then turn the key to turn on the device.

Fuel Filter Replacement - Diesel, Common Rail System

In older diesel engines, replacing the fuel filter requires bleeding the system. This can be done using a special light bulb placed on the supply lines or at the filter. In newer diesel engines, you can start the engine in a similar way to gasoline designs. Common rail fuel systems and unit injectors do not require bleeding. It is enough to turn the key to the ignition position several times.

How much does it cost to replace a fuel filter?

Replacing the fuel filter by a specialist only pays off if it is hidden in the tank or in another hard-to-reach place. Then there can be no question of self-replacement. The cost in the workshop can fluctuate around 80-12 euros, however, if you have your own filter in the engine compartment and will not change it yourself, you will pay a little over 4 euros alone.

It is better to change the fuel filter before damaging the injection pump and clogging the injectors

Impurities from the tank or present in the fuel can cause great damage to the fuel supply system. The worst consequences of a breakdown await owners of diesel engines. Chips or other elements can damage the smooth surfaces of the injection pump or clog the injectors. The cost of regenerating or replacing these elements is in the thousands of PLN. However, it is probably better to pay a few tens of zł or replace the filter yourself?