What is a fuel filter and where is it located?

The main role of the fuel filter is to remove various contaminants present in the environment, which makes it an important element of the fuel system. It provides high-quality protection of the injection system and engine from small particles that are present in gasoline or diesel fuel.

The fact is that there are countless tiny particles in the air that are enemies of the engine, and the fuel filter serves as a barrier to them. If they get into the engine, they can interfere with its proper operation and cause serious problems, such as a violation of the cylinder mirror, clogging of nozzles or nozzles, etc. That is why it is very important to regularly check the condition of the fuel filter and change it in a timely manner. The quality of the filter depends on what type of fuel we use and what the structure of our engine is.

A fuel filter traps particles such as sand, rust, and dirt that enter metal tanks for storing or transporting fuel. There are two types of fuel filters: for coarse and fine cleaning.

Coarse fuel filters

This type of filter removes fine particles from the fuel with dimensions greater than 0,05 - 0,07 mm. They have filter elements, which can be tape, mesh, plate or other type.

There are filters with a settling tank for rough cleaning. They enter the fuel through an inlet hollow bolt, also called an injector, which is screwed into the hole. Fuel passes through nozzles on top of the strainer.

Then it goes to the distributor and from there flows through the reflector to the bottom of the filter housing. Larger impurities and water accumulate at the bottom of the container.

Fuel passes through the nozzle and the hole to the fuel feed pump. The filter tank has a precipitator welded to it. Its role is to reduce the turbulent movement of fuel in the cup (so that debris accumulates in the sump). During vehicle maintenance, the sediment is drained through the plug.

Fine fuel filters

In a fuel filter of this type, gasoline or diesel fuel passes through it before the fuel pump injects. The filter cleans all impurities larger than 3-5 microns. The material of this filter is most often made of special multilayer paper, but can also be made of mineral wool impregnated with a binder, felt or other material.

The filter consists of one housing and two filter elements that can be replaced, as well as two vessels to which two bolts are welded. Their role is to secure the housing with nuts. Drain plugs are attached to the bottom of these bolts.

The fuel filter fine filter consists of paper filter elements. Their outer layer is made of perforated cardboard and has seals on the front surfaces. They are pressed firmly against the filter housing by means of springs.

In addition, the fuel filter traps particles, such as organic elements, sludge and water, which form as condensate on the walls of the fuel tanks, as well as paraffin, which undergoes a crystallization process in the fuel.

These elements either enter the fuel after refueling, or are formed under the influence of chemical reactions in the fuel. Diesel cars have more accurate fuel filtration. Nevertheless, this is not a reason to think that the diesel engine does not require timely replacement of the filter element.

Where is the fuel filter located and how does it work?

The fuel filter on most car models is located on the fuel lines between the injectors and the fuel pump. In some systems, two filters are installed: for coarse cleaning before the pump (if it is not in the fuel tank), and for fine cleaning - after it.

It is usually located at the highest point in the vehicle’s fuel system. Thus, air that enters from the outside is collected and returned with a portion of the fuel through the nozzle valve.

It is made of special paper, which is located in a steel container located in the engine compartment of the car. To find out where your fuel filter is located, consult your car manual.

The appearance of the fuel filter and its location depend on the model of your car. Typically, diesel fuel filters look like a thick metal can.

The spring-loaded valve opens in accordance with the overpressure prescribed by the manufacturer. This valve is adjusted by selecting the thickness of the shims located in the channel bore. The role of the cork is to remove air from the system.

Common fuel filter problems

If the fuel filter is not replaced on time, this will complicate the operation of the engine. When the separator is out of date, the crude fuel enters the engine, which degrades the efficiency of combustion and, therefore, the entire operation of the engine. This increases the consumption of diesel, gasoline, methane, propane-butane. Therefore, when changing the oil, it is recommended to change the fuel filter of the car.

The behavior of the engine directly depends on how clean the fuel filter is and how often we change it. When the fuel filter is clogged with dirt, this reduces engine efficiency. He does not receive the amount of fuel that the injection system is configured to, which often leads to problems with starting. Irregular replacement of the fuel filter also leads to an increase in fuel consumption.

One of the most important tasks of the fuel filter is water separation. This is due to the fact that if there is water in the fuel, it wears out the engine even more and shortens its service life. Water has the ability to cause corrosion in metal cavities, deprives the fuel of its lubricity, creates damage to the injector nozzles and leads to inefficient combustion of fuel.

In addition, water creates the prerequisites for increasing bacterial formation. Water separation is achieved by combined fuel separator filters. As their name implies, they separate water from fuel.

This type of filter has a housing, also called a reservoir, in which water, separated from the fuel, is collected at the bottom. You can remove it yourself. The water contained in the fuel separator filters is separated in two ways.

Cyclone Cleaning

In it, the bulk of the water is removed from the fuel under the influence of centrifugal forces.

Cleaning with filter media

Due to this, water mixed with fuel is retained by a special filtering material. Filtered water accumulates on the surface of the filter element and flows into the tank. When this tank overflows, in addition to water, fuel begins to flow into it under pressure.

When this fuel begins to pass through the filter material and enters the engine, increased pressure occurs. This happens regardless of how the fuel separator filter works.

It is important to note that in diesel filters, water accumulates at the bottom. When replacing the fuel filter, it is useful to check for a drain valve. This will help us drain the accumulated water. However, if there is a small amount of water at the bottom, this is not a cause for concern.

In winter

In the winter months, it is useful for the fuel filter to have a heater, because when it is cold started, ice or paraffin crystals can get into it. Paraffin, in turn, can clog the filter material, making it unsuitable for use. The fuel filter can be heated in several ways.

Electric heating

A heater operating in a certain temperature range is mounted on the filter housing. It turns on and off automatically, as it has a thermostat.

Return heating systems

This type of heating is designed for use in harsh weather conditions. In the fuel systems of some vehicles, heated unused fuel is returned to the tank. Such a highway is also called a "return".

So, the fuel filter provides high-quality cleaning of gasoline or diesel fuel. This contributes to the stable operation of the motor, therefore, timely replacement of this element is recommended.

Questions and answers:

How should the fuel filter fit correctly? Most fuel filter models indicate which direction the fuel should travel. If the filter is installed incorrectly, fuel will not flow.

Where is the fuel filter located? A coarse fuel filter is always installed in the fuel tank in front of the submersible pump. On the highway, it is located in the engine compartment.

What does a fuel filter look like? Depending on the type of fuel (gasoline or diesel), the filter can be equipped with a separator (water sump) or without it. The filter is usually cylindrical and can be transparent.