What is the function of the fuel filter and when should I change it?
A car is made up of thousands of complicated and complex parts – difficult for non-mechanics to understand. But the fuel filter is not one of them: it is as simple as it is essential. Still, many drivers often wonder what the fuel filter does. And, more: “when should I change it?”. For more references, check out: bad fuel filter symptoms
Unlike a car engine, which has several gears and cylinders, the fuel filter is composed of steel, aluminum or even plastic and also a paper mesh based on cellulose fibers. This mesh is responsible for filtering the fuel that arrives from the vehicle's tank, removing its impurities, and then it sends it to the engine.
The filter is therefore always located between the gas tank and the car's engine – usually at the rear of the vehicle.
But what is the function of the fuel filter exactly?
The question may sound a bit obvious, but it is necessary to understand what are the threats that the filter must fight – why it is really there.
We know, until now, that fuel (whether it is gasoline or ethanol) is stored in a tank, and that the car's fuel pump takes it to the filter. This last piece retains the “impurities” that come to meet it, through the cellulose mesh, and then the rest of the fuel goes to the engine injectors.
But what are these impurities?
They can be either in the fuel or in the car's own tank, and are dirt particles like dust, rust and even water. These residues may have accumulated there in various ways: they could already be inside the tank, they could have accumulated during transport , or they could even be in the gasoline or ethanol itself.
There are many gas stations, for example, that sell adulterated fuels . This can create a lot of work for the filter and can end up overloading it. So it will need to be changed much more often.
It is good to remember that impurities are always accumulating in the filter mesh, reducing the passage of fuel, and that is why its periodic change is essential – even when refueling is done at reliable and safe stations.
The most serious and costly damages
A car can only function well when all its parts are in harmony and in good condition. As already seen, the main part dealt with in this text is a simple filter (a simple mesh) that helps to keep the fuel clean. However, when it is past replacement time, damage to the vehicle can be very costly.
It is very common, for example, that there is damage to the fuel pump. This is because, when the filter is no longer working properly, gasoline or ethanol passes through the mesh with more difficulty until it reaches the engine, and the pump is overloaded. After all, it has to make a much greater force to transport the same material until it reaches the engine.
It is also common, when the filter is not in good condition, for debris and impurities to reach the electronic injection nozzles (responsible for spreading the fuel through the combustion chamber). Cleaning, in this situation, is more complicated.
To give you an idea, the injection nozzle decarbonization (cleaning) kit costs around R$ 50.00, and the nozzle itself costs around R$ 100.00 (when it is no longer expensive).
The filter itself usually costs only R$30.00 – and there are some for up to R$10.00, although the driver must always certify their quality.
What might seem more complicated – taking the car to the mechanic to check and change the filter – could turn out to be much easier and simpler than the consequences of not taking action.