Do-it-yourself particulate filter repair

In detail: do-it-yourself particulate filter repair from a real master for the site my.housecope.com.

The particulate filter is a metal cylinder inside which there is a ceramic heat-resistant matrix, which is coated with a catalyst consisting of many channels. Channels and perform the main function of purification - they retain small soot particles.

The porous structure of the channels allows you to trap the smallest particles. Exhaust gases pass through the filter and soot particles settle on the walls of the matrix. The particulate filter catalyst oxidizes unburned hydrocarbons and neutralizes carbon monoxide.

The diesel particulate filter is repaired if light does not penetrate through the filter. If it penetrates, then you can leave the old filter for a while. In addition, if the particulate filter is removed in time, the noise level will significantly decrease, the air flow will be uniform, so there will be no problems with the engine. Also, the engine will be protected from water ingress.

Particulate filter repair is needed, since particulate filters have a short service life, approximately 120 - 200 thousand km. Original filters are not cheap, so you can repair the particulate filter using regeneration. Forced regeneration, or filter cleaning, is started by the car.

The particulate filter is regenerated in such a way that the soot particles are burned out. The engine control unit increases the temperature inside the filter to six hundred degrees. Additional fuel is then injected into the filter. It burns in the particulate filter. Due to the increased temperature in the filter, an oxidation reaction of carbon occurs.

Video (click to play).

Diesel particulate filter regeneration is recommended at a speed of 80 km/h for forty km of driving. In some vehicles, the control unit is able to change the parameters of the engine. Therefore, columns of smoke can be observed near the cars. The diesel particulate filter receives fuel and heated exhaust gases.

The particulate filter warms up to seven hundred degrees. The soot particles burn out and the particulate filter is cleaned. It is important to make it on time, otherwise the filter will become completely dirty, and both the health of the driver and passengers, and the condition of the engine will suffer from this, due to a lack of oxygen, it will worsen its work. Repair of the particulate filter is possible in cases where it is taken on time. If the filter is completely dirty, it must be replaced with a new one.

At the end of the last century, environmentalists began to vehemently fight the owners of automobile companies and oil rigs, accusing them of excessive environmental pollution. In order to somehow calm the indignation of the fighters for a clean atmosphere for a while, the designers developed such a detail as a particulate filter. With the beginning of its use in the automotive industry, we stopped breathing soot, which is released during the combustion of diesel fuel in the engine.

The particulate filter is used in the design of diesel engines. It allows you to thoroughly clean the exhaust from various unwanted impurities, as it has a fine cell structure. This detail makes the environment a little better.

Despite all its usefulness, the particulate filter has one significant drawback - the need for frequent cleaning. The fact is that it is spontaneously cleaned only when driving at high speeds, which is not always possible for a motorist. Experts recommend after every 150 km driven a car on the highway.

However, even with this advice, replacing the particulate filter is inevitable.It is not completely cleaned, and its high degree of contamination can lead to the following undesirable consequences:

reduction in diesel engine power and increased fuel consumption;
overheating of the motor in the hot season;
reduction in the life of the motor, which leads to its breakdown.

If the particulate filter is not very dirty, that is, you have timely determined the initial stage of contamination of the filter element, then it can be cleaned. This process will improve the throughput of the element, and therefore solve problems with insufficient motor power.

On the video - cleaning the particulate filter:

The particulate filter is cleaned by car mechanics at every self-respecting service station. Here pollution in the early stages will be removed quickly and inexpensively. If you want to save on the services of professionals, you can always clean the device yourself.

This part, like a bee hive, consists of a large number of small holes, which eventually become clogged with soot, soot and other combustion products of diesel fuel. To clean it, a special additive is used, which is added to the tank of the car and mixed with diesel fuel. When driving on such fuel, the filter element is cleaned.

There is also a second option. In it, to clean the filter, it is supposed to be removed. After that, the part is soaked in a special chemical agent and blown under high pressure. After such washing, the part is installed in its original place.

As you can see for yourself, the addition of additives to the fuel avoids vehicle downtime and is therefore a more popular way to clean the diesel particulate filter.

If the particulate filter of your car is in a deplorable state, then the only way to save the environment and not lose engine power is to replace it with a new one. In this case, you will pay not so much for the work as for a new part.

A new filter element costs a lot of money, especially when it comes to original parts. The replacement of the particulate filter itself consists in removing the old one and installing a new one. Motorists carry out such manipulations quite rarely, again, due to the high cost of the part itself.

Another solution to a dirty particulate filter is to remove it. It will reduce fuel consumption, not drive from time to time at high speeds to regenerate this part, increase the power of the car and permanently get rid of the risk of engine breakdown due to clogging of the filter part.

Self-deactivation of the particulate filter consists of two stages. On the first one, you perform its physical removal, and on the second, software.

At the first stage, you will need to cut out a compartment with this element and a catalyst. In their place, you can install a flame arrester or simply weld a piece of pipe. Installing a flame arrester will increase the durability of the muffler and exhaust system, engine power and change the exhaust sound to a lower one.

On the video - removing the particulate filter:

At the second stage, in order to avoid an error in the electronic engine control unit, temperature sensors and a lambda probe must be welded into the welded piece of pipe. After getting rid of the particulate filter, you will need to chip-tun the car. This procedure will first of all allow you to get rid of gray-black smoke emissions.After removing the filter part, your engine will become less whimsical to maintain. It is also worth noting that you will immediately lose the warranty on the car.The particulate filter allows you to rid the environment of harmful impurities of fuel, soot and smoke exhaust. If it becomes dirty, you will have a choice of three options: replace it, clean it, or turn it off. Each of these options has its pros and cons.Having made a decision, remember that in the future your children and grandchildren will live on this planet. Image - Do-it-yourself particulate filter repair

Modern diesel vehicles have many design solutions for cleaning engine exhaust gases. These include the EGR exhaust gas recirculation system, and one of the solutions is the widespread installation of DPF particulate filters. In the process of active operation, such a filter can quickly fail under certain conditions.

The main task of the filter element is to trap soot. The next step is the afterburning of accumulated soot deposits in such a way as to minimize damage to the environment. At the very beginning, the filter collects soot up to a certain point. This moment is determined by the difference in pressure in front of the element and after it. When the pressure deviates from the allowable limit and the filter capacity does not allow the exhaust gases to pass further efficiently, the diesel engine ECU activates the appropriate mode to burn off the accumulated soot.

Soot afterburning on a diesel engine is switched on under various conditions, which are individually set by the manufacturer of a particular model. These conditions are generalized by the fact that the diesel engine must have an average or high crankshaft speed and be in motion. The ECU gives the command to increase the amount of fuel at the time of injection. The result is an increase in the temperature of the exhaust gases at the outlet. With such an increase in temperature, the soot burns out. If the car is operated in urban areas with short trips at low speeds, constantly warms up in winter and is idle for a long time in traffic jams, then the self-cleaning mode of the diesel particulate filter simply does not activate. Constant exposure to such conditions leads to rapid clogging of the element.

The service life of the particulate filter directly depends on a number of factors and the individual operating conditions of the vehicle. A critically clogged element must be changed. It is worth noting that the cost of a high-quality new part is quite high. For this reason, the question of how to clean the diesel particulate filter has become acute.

The pollution process begins as a result of the combustion of diesel fuel in the cylinders of a diesel engine. Soot is a by-product of combustion of a mixture of diesel fuel and air. This soot is not particularly harmful to the filter, as it is a fine powder. When filtering on the grid, these particles simply linger.

The problem arises due to the presence of hydrocarbon particles in the exhaust that did not burn out in the working chamber. Hydrocarbons lead to the fact that the active formation of resinous deposits begins. Soot microparticles literally stick together with resin, resulting in accelerated carbon formation. Also in the soot there are also components of diesel engine oil in the form of metal sulfates, which are formed after the combustion of oil that has entered the cylinders.

Sulfates in the exhaust appear due to the fact that metal-containing additives are included in the basic composition of the additive package for diesel oils. This is especially true for universal motor oils, which can be used equally for both diesel and gasoline ICEs. The result is that the diesel self-cleaning system is not able to remove dense deposits on the particulate filter.

The service life of the particulate filter directly depends on the total number of self-cleanings that the ECU initiated. The more often the part is self-cleaning, the greater the amount of platinum catalyst burns out under the influence of elevated temperature.

The main advantage of the constant maintenance of the diesel exhaust system is the economic aspect, as well as the possibility of operating the engine with consistently optimal performance.If the diesel engine is in conditions that lead to increased carbon formation, then preventive cleaning of the particulate filter is much more profitable than driving without maintenance until the replacement itself. This is clearly reflected in the financial plan. A serviceable diesel engine with a cleaned filter always delivers full power, moderate fuel consumption, easy to start, does not harm the environment, the reliability and overall life of the internal combustion engine increase.

Additionally, you can extend the "life" of the part by using special additives in diesel fuel. Such additives make it possible to improve a number of parameters during the operation of a diesel engine. A separate group of additives is aimed at making the carbon formation process less intense, and is also aimed at reducing the total amount and lowering the temperature during the automatic self-cleaning of the cleaning element.

The diesel additive helps diesel fuel to fully burn out in the cylinders, which reduces the amount of soot in the engine exhaust gases. With self-cleaning, there is no need to heat the diesel catalyst for a long time, catalyst burnout in this case becomes less intense. If the motor is in good condition, good quality diesel fuel is poured in, and the additive is regularly used once every 2-3 thousand kilometers, then additional filter cleaning may not be required at all.

A common problem has led leading companies to develop ways to clean, prevent and protect diesel particulate filters. There are two main approaches to improve the efficiency of diesel filter element regeneration:

cleaning the diesel particulate filter without removing it;
flushing the diesel particulate filter with removal;

It is also necessary to know exactly how to flush the specified element of the diesel engine exhaust system, since the use of cleaning agents not intended for this can permanently disable the contaminated element.

Let's start with a method that involves removing the particulate filter. This washing procedure usually requires about 8 hours. After the completion of the dismantling of the filter element and its removal from the machine, the housing is completely filled with a special washing liquid for cleaning. Such liquids for washing the particulate filter are widely available on the market. The market leaders are the products of Liqui Moly, Luffe, PRO-TEC.

Liquids are made from petroleum components, often packaged in 5-liter canisters. The average consumption for high-quality flushing of one particulate filter is at least 4 liters of composition. Moreover, the canister may have a special neck in advance, since then a hose will need to be connected. There are also variants of canisters equipped with a ready-made hose.

The principle of operation of the flushing liquid is based on the fact that the composition effectively dissolves the resins (aged for about 8 hours), on which the formed soot is held. The requirements of the fluid manufacturer must be carefully followed, as it is very important to wait the necessary time for the flush to fully affect the soot.

Further, the released soot is simply washed off with an ordinary jet of clean water under pressure, which is fed to the filter. After that, the filter is dried and put in place. The resin solvent itself is made on an oil basis, is well washed with water, and does not harm the structure of the catalyst.The second way is to flush the particulate filter without removing it, which means working directly on the car. The filter part of a diesel car is equipped with pressure and / or temperature sensors. If the sensor is unscrewed, then it becomes possible to supply flushing fluid.Since flushing is carried out on a car, manufacturers take into account the possible risk of ignition of the flushing compound. In such conditions, the use of petroleum products is no longer possible. For cleaning, water-alkaline solutions are recommended, paired with a flushing fluid.This liquid neutralizes harmful alkali after the solution completes the cleaning process. The supply of liquid to the body of the element is carried out using a gun specially designed for this purpose. A straight or curved probe is also used, and a spray nozzle is additionally provided.A set of fluids, a gun, sprayers and probes allow you to work with almost any model of a diesel car equipped with a particulate filter. Cleaning in this way involves a phased dosed supply of cleaner through the sensor hole. The most commonly used place of installation is the pressure sensor, which is located in front of the element. The machine is warmed up in advance, then the filter is allowed to cool to an approximate mark of about 40 degrees Celsius. The fact is that the alkaline cleaning composition is most effective at this temperature.For cleaning, about 1 liter of liquid is required, which is left in the element housing for 15 minutes. The high pressure spray gun is connected to a straight or curved probe that is inserted into the sensor opening. The cleaner is sprayed intermittently (up to 10 seconds spray, up to 10 seconds pause) directly onto the surface of the particulate filter. The working pressure when spraying should be about 8 bar. It is desirable to rotate the probe during the spraying of the composition, as well as move it back and forth to achieve a better quality of applying the cleaning liquid to the filter element matrix.Next, rinse aid is sprayed in the same way, which neutralizes and rinses off the cleaner. It will take about 500 ml. cleaning compound. Flushing takes place using the same spray gun, similar time intervals of pauses between spray stages are observed. Thanks to this approach, the soot is distributed over the surface of the matrix more evenly. The result is that the soot can be burnt off much more efficiently during the automatic self-cleaning process.Upon completion, the pressure sensor is installed back into place, the diesel engine starts and warms up. After that, you will need to start the self-cleaning mode in order to burn through the soot particles freed from the bonding resins. This can be done both “naturally” and by force. In the first case, it will be necessary to actively operate the diesel engine on the go at medium and high speeds for about 20 minutes, so that the electronic engine control unit independently initiates the start of the particulate filter regeneration process.

Purpose and arrangement of the exhaust gas recirculation system. EGR valve, high and low pressure EGR system. Malfunctions of the recirculation system.

Means and methods for flushing the engine before changing engine oil. Whether it is necessary to flush the engine, with what compositions and in what cases it is necessary.

Independent implementation of diesel fuel heating: fuel intake, coarse and fine filters. Installation of heating elements. Flow heating.

Features of operation and maintenance of the internal combustion engine. What needs to be done so that the engine runs as long as possible without a belt.

Soot in the engine occurs as a by-product of fuel combustion. Although its volume depends on the ratio of air and fuel, it is still formed in one quantity or another. A particulate filter helps to prevent environmental pollution, which retains about 97% of all particles. He does not allow her to go outside, and in the future simply burns when the engine is running. This burning effect is called regeneration.

The particulate filter has a simple device based on a cellular membrane. It is made of silicon carbide and consists of many small channels connected by bridges. The use of a similar design and material provides the filter with the following characteristics:

high temperature threshold;
resistance to temperature fluctuations;
a large resource of work;
high strength.

Thanks to this, it is able to perform its task for a long time, intercepting miniature soot particles in the exhaust path.

The principle of operation of such a device is no different from a conventional filter. Soot particles simply remain in the membrane system without escaping. Since all exhaust gases are passed through this filter, the system is able to block a significant part of the soot in the exhaust process.

But it is important to remember that the filter is constantly filled with soot particles, which leads to a decrease in throughput. To eliminate them, regeneration is carried out, which is provided for by the very structure of the element.

When the car is running, it is important to maintain the throughput of the filtration system. Therefore, sensors are often built into the system that determine this parameter and, if possible, burn soot in the element. The problem is that burn-in is only possible when driving for a long time at high speeds, so it does not turn on when driving short and winding distances.

For this reason, riding within the city does not give a chance to regenerate. Burning occurs to a minimal extent, keeping most of the blockage in the system.

Therefore, it is important to monitor the condition of the system and monitor for possible symptoms of a clogged particulate filter:

increased fuel consumption;
traction reduction;
consistently high oil level;
irregular operation of the system;
smoky exhaust;
possible hiss while driving.

And the main sign that you should pay attention to is the filter icon on the dashboard. If it catches fire, then it is urgent to go for diagnostics.

Driving with a clogged filter is contraindicated for any vehicle. With an abundant amount of soot precipitation in the system, various elements may break down. The oil is clogged, which leads to a decrease in the efficiency of the engine. Over time, the gas recirculation system is destroyed, and in the future, the engine itself breaks down.

The principle of regeneration is simple: the microparticles clogging the membrane burn out at temperatures above 500°C. Therefore, the cleaning process consists in raising the temperature in the system to such a point that the exhaust gases can burn out the pollution. This is only possible at full engine load.

There are two types of membranes that differ in location: FAP and DPF. The first type is located at a distance from the engine, and the exhaust gases cannot heat up the particles sufficiently. Therefore, a fuel additive is used for such a task.

Since the exhaust gases travel a long way from the engine to the cleaning element, they simply cannot burn the blockage. The temperature is not enough for such a task, so it is necessary to increase it. For this, special cerium-containing additives are used. Cerium microgranules allow you to heat gases to the required level, thereby destroying the blockage.

The additive itself is cerium microgranules in a special substance. This form allows you to maintain its structure until it hits the filter. Initially, gases only evaporate the shell of the granules, releasing cesium. When it hits an already heated membrane, it ignites sharply, raising the temperature of the surrounding gases to 1000 ° C. Such a bar is safe for the system, because the heating occurs locally.

The second type of filters is located near the engine, so the required temperature level is reached without additional tools. Exhaust gases almost immediately enter the filter, thereby burning out the blockage and continuing on their way.

It is important to note that in both cases it is recommended to increase the temperature of the exhaust gases through the engine control unit. This will increase the cleaning efficiency.

This cleaning procedure occurs only at full speed, so it is important to periodically squeeze the engine to full power. But it is worth remembering that regeneration does not need to be carried out daily, the frequency depends only on the intensity of soot formation.

If the filter has been used in adverse conditions, thereby clogging, then it is forbidden to use it. It will simply destroy the system and the engine, which will result in a major overhaul.Therefore, with complete blockage, it is necessary to undergo a forced regeneration procedure.

Forced regeneration can be started by special equipment, often present in service centers. It allows you to quickly eliminate blockages by connecting a cleaning system. However, it is not always possible to turn it on. In cases where the filter is overfilled, the cleaning system will not turn on.

If this happens, then washing with the help of special tools will help here. Often it allows you to eliminate most of the soot, after which it is possible to connect regeneration.

Washing is carried out in two ways:

without removing the element;
complete flushing with removal.

In the first case, you need to take a spray gun and a flexible tube, as well as a filter cleaner. For such tasks, TUNAP MP 131 fluid is suitable. A pressure source is also needed - a compressor. The filter is accessed through a previously removed temperature or pressure sensor. It is necessary to thoroughly clean this element, the approximate consumption for one cleaning is up to a liter of liquid.

Next, you need to remove the liquid with TUNAP MP 132 concentrate. After that, the cleaning procedure is completed, you need to return the sensor to its place and regenerate the filter using standard methods. If the procedure did not help, then it is necessary to carry out a complete flush with the removal of the element.

The second method is to completely remove the filter and wash it. First you need to remove the filter from the system and open it. Next, it must be washed with special tools like DPF Cleaner. They eliminate soot and oil residues, as a result of which they are easily removed under the pressure of water. Such cleansers are washed off with water. Cleaning can be supplemented with special cleaners such as PRO-TEC DPFCatalyst Cleaner. However, this depends on the situation.

After completing the procedure, you need to dry the filter and install it in the car. Next, it is worth checking its condition and starting regular regeneration. But it should be borne in mind that flushing is far from always able to help against blockages. If the available methods did not help, then you will have to purchase a replacement.

It is recommended to replace the filter after passing 180 thousand kilometers. This point can be delayed through cleaning and regeneration, but this element cannot serve forever, and the use of a clogged or bad filter will lead to soot entering the system, which will necessarily result in high repair costs.

And for a better understanding of the effectiveness of washing particulate filters, it is recommended to watch this video. Here, a clogged filter segment was cleaned using Luffe. The stages of the procedure and the effectiveness of such washing are clearly shown:

Every diesel car has a particulate filter. If it is not cleaned, this will lead to serious consequences for the machine.Its clogging leads to the ingress of particles into the environment, so that it is harmful to humans, and on the machine this affects problems with the electronics signal on the dashboard, a decrease in traction and dynamic characteristics, interruptions in the operation of the motor, and an increase in oil level.That is why diesel particulate filter cleaning is carried out.The diesel particulate filter (DPF) is a part used in the design of such engines to purify exhaust gases from unwanted impurities. Image - Do-it-yourself particulate filter repair

It reduces the amount of emissions into the environment by accumulating harmful substances and soot. But since it is the ultimate reservoir for their accumulation, it must be cleaned periodically in order to regenerate the DPF.

This process burns off excess soot deposited in the filter, reducing emissions and helping to prevent black smoke.

If the DPF becomes clogged with soot or an error occurs in the system, an orange light will usually appear on the dashboard.

Short trips at low speeds are the main cause of blocked filters.

This is why automakers often recommend opting for a gasoline-powered vehicle over diesel (and why diesels are rare in the urban automotive sector).

The filter is able to clean itself only when driving at high speeds, and if the driver only drives within the city, this becomes impossible. Any master at the service station will tell you that cleaning should be done every 150 km.

Oil can also cause contamination. Some of them contain additives that can actually block diesel particulate filters.

All this can lead to damage to the particulate filter, as well as when using low-quality fuel and even when driving the car often on low fuel levels, as the car can avoid DPF regeneration to save fuel.

There are several ways to remove soot from a DPF. This is passive and active regeneration or the use of special tools.

How to clean the particulate filter? Passive regeneration occurs when the vehicle is driving at high speed on the motorway. This allows the exhaust temperature to rise to a higher level and to burn off excess soot in the filter.

Therefore, it is recommended to regularly give your diesel car a 30-50 minute drive at high speed.

However, not all drivers do this regularly, which is why manufacturers have developed an alternative form of regeneration.

This method means that extra fuel is automatically injected as part of the car's ECU when the filter reaches a predetermined limit (usually around 45%) to raise the exhaust temperature and burn off the accumulated soot.

Problems can arise if the journey is too short, as the regeneration process may not complete completely.

If so, the warning light will continue to indicate that the device is still partially contaminated.

You will know if active regeneration is taking place, because it will be manifested by such signs:

pungent smell of exhaust gases;
increased idle speed;
cooling fans not working;
slight increase in fuel consumption.

Cleaning the device is not a problem, the main thing is to know how to do it correctly.

A cleaned filter does not cause the indicated problems. The motor engine runs without interruption, and there will be no other problems either.

What to do if neither active nor passive regeneration works?

If the warning light continues to flash, cleaning has failed. It is required to replace the part or remove it for washing with professional products.

Do not fill diesel oil until flush cleaning fluid has been used.

How to clean diesel particulate filters?

First you need to dismantle it, and then use special fluids. But thanks to these funds, you can do without removing, because this is the most difficult: PRO-TEC, Luffe, Liqui Moly.

They reduce the formation of soot during fuel combustion. Cleans and regenerates blocked soot filters without dismantling.

The fuel system of a car is very sensitive to contamination. This contamination can increase engine noise, fuel consumption and reduce engine lubrication and power.

Using fuel flushes on a regular basis will help keep the fuel system clean and the engine running more efficiently, reducing fuel consumption and emissions.

Particulate filters are better to clean than to run and then change to a new part. They are expensive. Carry out regeneration in accordance with the requirements and this problem will not affect you.

The particulate filter is a necessary element of the exhaust system for all diesel vehicles, neutralizing combustion products and controlling the emission of harmful substances into the atmosphere.

Since 2005, the European auto industry has introduced the EURO 4 standard, which modern cars must comply with.That is why almost all diesel cars are now equipped with a particulate filter.

Its device is quite simple: a metal cylinder, inside of which there is a heat-resistant ceramic filler with cells where particles settle. If they are completely clogged, then it is necessary to remove the particulate filter. Moscow can offer a lot of car services where they provide this service.

But first you need to make sure that the filter really needs to be replaced, because there are two types of auto cleaning.

Diesel particulate filter regeneration

Firstly, when driving on the highway, the so-called “passive regeneration” occurs, when the soot in the filter burns out under the influence of high temperature.

Secondly, in urban conditions, the detector independently determines the degree of contamination of the filter and starts its regeneration: it burns out the residual mixture in the catalyst. That is why the filter is usually placed after the catalyst.

It is easy to understand that passive regeneration has begun - thick smoke begins to pour out of the exhaust pipe, fuel consumption and the number of idle strokes increase.

But such cleaning is only a temporary solution to the problem, yet the particulate filter is a consumable item that must be replaced in a timely manner. It should not be delayed with the change of a burned-out filter, because its failure can lead to a breakdown of the catalyst or the EGR valve.

Remember that the filter should be changed after about 80-100 thousand km, and some cars start having problems even at 50. Determining that the particulate filter needs to be replaced is quite simple:

Fuel consumption has become higher;
Unstable operation of the engine is detected;
The oil has a high level indicator;
The exhaust is heavily smoked.

If you notice these signs, then it is worth removing the particulate filter, the price for this service may vary from different car services, but only slightly. Full dismantling may be the best solution in Russia, where there is no strict control of air emissions. After removing the filter, it is necessary to reflash the electronic engine control unit.

When choosing this option, remember that a car without a particulate filter will comply with the EURO 3 standard, which is not enough for European countries. Those. if you decide to go abroad in your car, and the filter is out of order, you will have to replace it with a new one or clean it mechanically.

Video (click to play).

Replacement is the most expensive particulate filter repair. This part is quite expensive, cleaning will cost less (dismantling and flushing), but this is a temporary measure that allows you to forget about the problem for a short time.