Fuel filters - how to choose, where they are, when to change them

How does a fuel filter work?

Fuel filtration on modern cars is two-stage. In front of the fuel pump, a fine nylon receiving mesh screens out contaminant particles. And then the final screening of particles larger than 10 microns (for gasoline) is carried out by a fine filter.

The fuel module of the Lada 4x4 consists of a mesh fuel receiver and a fuel pump.

The fuel module of the Lada 4x4 consists of a mesh fuel receiver and a fuel pump.

Fuel consumption

Fuel consumption is the first obvious sign of a clogged filter. Every driver can determine it, just drive the estimated distance. Experienced motorists know how much gasoline is consumed on a particular road and distance. Obviously, if the filter is clogged, the consumption will increase noticeably. Fuel enters the internal combustion engine in small quantities; due to the concentration of debris in the filter, the composition of the combustible mixture changes. This explains the fact that the power and speed of the car decrease; the driver sometimes needs to press the accelerator harder.

There is also a special device that allows you to monitor the process of clogging of the TF, signaling the need to replace it. This tool can be used to determine when replacement will be required and will reduce damage to the fuel supply. This is a sensor that allows you to reduce wear on the fuel supply system, as well as reduce the cost of consumables and replacement elements.

Fuel filter and fuel consumption

However, such indicators are not installed by all vehicle manufacturers. However, it is not difficult to detect a clogged filter without a sensor. In addition to the above characteristics, the clogged TF can be calculated directly. To do this, you must first find it: on most cars it is located near the gas tank under the bottom. Then loosen the fixing clamps, lower the end of the fuel drive into a glass container, and be sure to place the car itself at neutral speed. In this case, the engine must operate in idle mode - if fuel flows at a lower speed than from the tank, it means that the fuel pump is clogged.

In fact, replacing the TF is not particularly difficult, especially if we are talking about a gasoline unit. It is necessary to prepare tools, which include a set of screwdrivers, gloves and a container for collecting liquid from the old TF. To avoid making any mistakes, it is recommended to use the instructions for a specific car. Installation of the TF must be carried out strictly according to the instructions. The new filter must be installed according to the direction of fuel movement.

Where is the fuel filter installed?

As for the location of the fine filter, automakers' opinions have changed over time. In the beginning, all filters were installed under the car's underbody or in the engine compartment and were easily accessible for replacement.

Then (increasingly) the filter began to be installed in the fuel module. This solution is, of course, more compact and convenient for cars. But replacing the filter is either not provided at all, but only as part of the module, or it involves a large amount of work to dismantle and completely disassemble the module. Moreover, the fuel module of some cars cannot be removed without dismantling the tank, and this is an even more ambitious task.

Instructions for replacing the filter

After completing all the preparatory work, you need to unscrew the old block using a special key. If the thread is stuck, which often happens, you can remove the filter element using an adjustable wrench, but in this case the body of the unit will probably be deformed. After removing the old filter and waiting until the residual oil leaves the engine, you can begin to change the block.

The area around the threads on the engine should be thoroughly wiped with a rag, and new engine oil should be poured into the new filter, as this will significantly improve the result of replacing the cleaning element and fill the channels faster. The seal ring on the filter cover also needs to be lubricated. Next, you need to carefully screw in the new filter, usually ¾ of a turn.

It is better to screw in the new filter by hand, and not too tightly, since it will be difficult to remove it later when replacement is required. The new block, installed in place, must be thoroughly wiped with a rag so that there are no leaks. Next, you need to start the engine for about 2-5 minutes, after which you need to check for leaks in the filter area. If everything is in order with the new unit, you should check the oil level and, if necessary, add some of the new one.

To keep your engine running, you need to know not only how to replace the filtration unit, but also how often it needs to be done. Depending on individual characteristics, the oil must be changed after every 10-20 thousand kilometers. If possible, it is recommended to replace the oil filter every 5-7 thousand km. As practice shows, in older cars the oil and filter element need to be changed more often.

Diesel fuel filter

So far we have been talking about gasoline filters. Diesel fuel filters are always installed separately from the fuel tank, because, in addition to more frequent replacement, they also need water sensors, a water drain plug and, often, a heating system.

Fuel filters for diesel engines.

Fuel filters for diesel engines.

Causes of clogging

If the fuel filter on a VAZ is clogged, the symptoms will be similar to those described above. This is a drop in power, failures, and unstable operation of the power unit. If the fuel filter is clogged, symptoms can especially appear on used cars, which are often purchased by newbies.

Buying a used car can save you money. But not every previous owner took good care of the car, did not skimp on replacing consumables, or bought high-quality consumables. In addition, given the quality of the fuel that is sold at most gas stations, many are surprised how engines running on this fuel even work. This is where a clogged fuel filter will show itself. Symptoms will definitely appear.

So, if the car is often refueled at unknown stations, the filters need to be changed more often. Fuel trading is a huge business where, first of all, you need a good return on investment. This can only be provided by well-known fuel companies. As for small fuel brands and gas stations, this gasoline may contain various debris, octane-boosting additives, tar, and much more. This is the main reason why filters become clogged.

What happens if the fuel filter is clogged?

The filters are, of course, damaged by the dirt that gets into the tanks of our cars along with the fuel. And it’s not the oil refineries that are to blame. Fuel can become contaminated during storage and transfer. And the driver will feel the clogging of the fuel filter by the behavior of the car, and first in those modes where the instantaneous fuel consumption of the engine is maximum. These are driving modes at high speeds and intense acceleration. In this case, the engine will lose traction and operate intermittently, although at idle and in “quiet” modes everything will look decent.

Replacement frequency

There are certain service periods prescribed by manufacturers. But in fact, taking into account the quality of the fuel and the condition of the roads, it is advisable to look at the mileage and the condition of the engine. This means only one thing: no one will give you specific dates. Hence the conclusion: if the fuel filter is clogged, then it needs to be changed. This operation is not so expensive as to jeopardize the condition of the entire machine.

The condition of the system through which gasoline circulates largely determines the productivity and service life of a car engine. Despite its simple design, the filter element has a significant impact on the dynamic characteristics of the vehicle. A clogged fuel filter adversely affects gasoline consumption, which is important for every car owner.

As the vehicle operates, the fuel filter gradually becomes clogged. As a rule, this is due to the low quality of the mixture used. As a result, the fuel filter insufficiently purifies gasoline, which seriously affects the operation of the car’s most important system. Not every car owner can promptly detect a faulty filter element. A slight blockage is not very noticeable when the motor is running. However, when the fuel filter is worn out, impurities enter the car engine, which settle in the cylinders and reduce the productivity of the internal combustion engine.

Considering the fact that the fuel filter is important for the operation of the most precious system of a car, every car enthusiast should know the frequency and technology of its replacement.

Undoubtedly, the period of operation of the element in question depends on how high-quality gasoline you use. Despite the claim of some manufacturers of modern cars that the fuel filter can clean the mixture throughout the entire period of operation of the car, it is worth performing diagnostics from time to time. As practice shows, replacing the fuel filter is an inevitable procedure for any car. In order to ensure proper engine performance and maintain its service life, it is worth diagnosing and replacing a faulty fuel filter every twenty thousand kilometers. Replacing the fuel filter will not only restore the dynamic and speed characteristics of the car, but also restore natural gas mileage.

How often should the fuel filter be changed?

The frequency of routine filter replacement is primarily determined by the vehicle manufacturer. For some manufacturers this is 30,000 km, for others - 120,000 km. Moreover, frequent replacements are usually recommended by manufacturers who place the filter outside the fuel tank. You should only change the fuel filter ahead of schedule if you are sure that foreign mechanical particles or a large amount of water have entered the tank. In this case, you should also rinse the tank and possibly replace the fuel pump.

Diesel engine fuel filters have the most difficult time in winter: after all, thickened fuel must pass through the filter material. That is why it is better to carry out preventive filter replacement on a diesel car in the fall. This is due to the fact that the filter capacity, already reduced by clogging with solid particles, will be insufficient to pass the cold, thickened fuel.

Frequency of replacement of gasoline filters of some manufacturers, thousand km:

• Volkswagen 30 (remote filters)
• Renault 120
• Kia 60
• Hyundai 60
• Lada 30 (remote filters), 120 (built-in filters)

Some tips for replacing the fuel filter:

• Refuel at proven, or even better, branded gas stations.
• Try not to pour fuel into the tank immediately after the fuel has been drained from the tanker at a gas station, because the fuel in the tank is agitated and dirt is more likely to get in.
• Do not pour fuel into old, rusty cans.
• Change fuel filters on time - then a malfunction will not catch you on a long journey.
• Wash the fuel intake strainer at the pump inlet: this will extend its service life.

Tell us in the comments if you have encountered problems related to fuel filters? Good luck on the roads everyone!

Fuel filter: should I change it or will it do the same?

Design and features of oil filters

All oil filters have approximately the same structure and set of components, regardless of what brand of car they are intended for. Most filter elements have the following components that perform specific functions during the cleaning process.

1. Frame. This element does not directly participate in the process of cleaning engine oil, but serves as protection against mechanical damage to parts located inside it.
2. Holes for filling and draining oil. As a rule, the holes located at the edges are designed to allow free entry of oil for cleaning. The central threaded hole serves to drain cleaned lubricant into the engine. A bolt is used to secure the filter cylinder to the engine.
3. Anti-drainage valve. This element is extremely important, as it prevents the oil from draining back into the filter, because, as a rule, this cleaning element is located in the middle or lower part of the engine. The thing is that after stopping the car, the pressure rapidly drops, and the lubricant under the influence of gravity can flow down, but the anti-drainage valve prevents this.
4. Oil filtration material. Filters from different manufacturers use microfibers made of synthetic material or cellulose, and in some cases combinations of both, as such material. To impart rigidity to the filtration material, special resins are often used. This material is folded into an “accordion”, which can significantly increase its area, cleaning properties and durability.
5. Central pipe. In most cases, it is made of steel, since it is through this element that purified oil is discharged into the engine. However, in some cheap options, the central tube is made of plastic, and this is not very good, since it may burst at the attachment point while the car is moving.

Oil filter device

• Safety valve. This element serves to reduce elevated pressure levels, if any. Under certain conditions, the pressure inside the unit can increase significantly, which can not only lead to the destruction of individual elements located in it, but also cause depressurization of the device.
• Filter cover. It is equipped with a special sealing ring that ensures the tightness of the entire structure.

Possible faults

The symptoms of a clogged fuel filter are quite varied. Please note that the following signs may indicate not only a breakdown of the filter device, but may also indicate the causes of a malfunction of the control system. To be on the safe side, you can make sure that the reason is in the fuel filter using the following method: take a pressure gauge and connect it to the nipple located on the fuel injector frame, then start the car and measure the pressure of the fuel mixture. If the pressure gauge shows parameters below those provided by the car dealer, we can talk about a fuel filter malfunction.

Clogged filter

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When the throughput of the filtering device decreases, interruptions in the operation of the power unit are observed:

• fuel consumption increases;
• the car stalls at idle;
• failures in engine operation are observed when the speed increases;
• it is difficult and sometimes impossible to start the engine;
• The power of the power unit decreases, it begins to triple;
• it is possible to brake the car while driving without pressing the brake pedal;
• When moving up an inclined plane, the vehicle jerks.

All these signs are observed if the filter is clogged; its increased resistance to the intake air flow creates additional load on the engine.