Where to muffle the EGR valve on a diesel engine. Where is the EGR valve - cleaning or how to muffle EGR

When switching to injection engines, it was noticed that the combustion temperature of the fuel-air mixture became higher than was typical for internal combustion engines equipped with a carburetor. And the return of part of the exhaust gases to the inside of the cylinders, oddly enough, allows you to slightly lower the combustion temperature, which leads to a decrease in the formation of nitrogen oxides. In general, EGR was invented to achieve good environmental performance. Note that this system is not activated all the time, but only at low revs or when starting from a standstill. But even then, her work noticeably "strangles" the engine.

What do we want to achieve?

It would seem that the exhaust system of a car is the simplest part of its design, and nothing can be improved here. But recently, a lot of "improvements" have appeared, allowing either to increase the operational parameters of the internal combustion engine, or to reduce the toxicity of the exhaust. The use of direct-flow mufflers, as well as active noise suppression systems - all this is necessary for the car owner, but not for the environment. But catalysts, sometimes used in conjunction with intercoolers, or systems of the "EGR" class, are already inventions pleasing to environmentalists. It is easy to see that the environmental friendliness of an engine cannot be improved without lowering its power, torque value, etc.

When we start a cold engine, the EGR valve remains closed and the exhaust gases cannot enter the intake manifold. As soon as the coolant temperature exceeds 80-90 C, this valve can be opened under certain conditions. The following tuning method is known: the exhaust gas flow to the EGR valve can be shut off, for which a plug is installed. Such tuning has easily predictable consequences:

The engine runs at full strength all the time (good);
The maximum combustion temperature rises (bad);
Only a mixture of fuel and clean air will be inside the cylinders (also good);
The catalysts will quickly fail (very bad!).

Based on the above estimates, it will be necessary to decide whether it makes sense to carry out the revision we are considering. It is clear that after its completion, the engine will be removed from the warranty, so we will leave the choice to the owner. First you need to make sure that the EGR system in the power unit really has a presence: it is used in conjunction with GDI engines, as well as with TDI "diesels". But the same cannot be said about turbocharged gasoline engines.

Tuning methods

Depending on the design of the engine as a whole, more precisely, on the design of the EGR system, different methods of closing the exhaust return flow channel are used. You can unscrew the pipe that supplies the exhaust gases to the EGR valve and install a plug (a circle made of thin PCB) over the rubber washer. In Japanese cars, the pipe is usually made of a copper alloy, and it is screwed to the valve body with a nut. Pay attention to the photo on the left, and everything will become clear.

GM vehicles use a two-piece EGR valve (see first picture). The top of this structure is attached to the bottom with two metric bolts. Having unscrewed them, you can see a metal gasket, one of the holes of which must be closed. In general, you can make a similar can gasket, but one that does not have a strikethrough hole. As you can see, nothing complicated. Some people recommend making the specified part from sheet chrome-plated brass.

Europeans are very concerned with protecting the environment. To reduce the formation of nitrogen oxides in internal combustion engines, an exhaust gas recirculation system is used.

An important element of this system is the EGR valve. It redirects part of the exhaust to the intake manifold and dilutes the fuel mixture with exhaust gases. As a result, the temperature in the cylinder drops, and the formation of harmful oxides is reduced.

Many car owners strongly doubt the benefits of an exhaust gas recirculation system, which, moreover, greatly complicates the diagnostic procedure. But

More precisely, the installation of the EGR valve plug does not affect the entire exhaust system. There is also an opinion that a bunch of unnecessary parts in a car are needed by manufacturers only to increase the cost of an iron horse and drivers put a plug on the USR valve without any problems.

When it is required to muffle the EGR valve

The EGR valve is muffled in two cases:

- to increase the power of the unit;

- in case of EGR breakdown, when the computer gives an error, and there is nothing to replace.

How to put a plug on the EGR valve?

The easiest and fastest way is to install the EGR valve plug. To do this, unscrew the fastening bolts and remove the valve. Further, according to the shape and size of the USR mount, you need to cut out the plug. Thick stainless steel is best, if not available, a tin plate will do. Do not forget that the exhaust temperature is quite high, the plate will be in hot conditions.

It is better to plug the hose suitable for the EGR valve with a bolt of the appropriate diameter. Install the cut-out plate instead of the EGR valve by placing washers under the bolts. The plug must be seated on silicone sealant and the bolts must be shortened as the EGR valve body is thicker than the plate.

After this procedure, which takes no more than half an hour, the computer should not give an error. But if the "brain" is stubborn, you will have to reprogram the BC. Each car model has its own nuances for installing the EGR plug.

Where is the EGR valve

The mentioned device stands directly on the engine of your car. In different models, the design and location may be different, however, you need navigate by the location of the intake manifold... Usually a pipe comes from it. The valve can also be installed on the intake manifold, in the intake tract or on the throttle valve block. For example:

The EGR valve for Ford Transit VI (diesel) is located in front of the engine, to the right of the oil dipstick

The EGR valve on the Chevrolet Lacetti is visible immediately when the hood is opened, it is located behind the ignition module

The EGR valve on the Opel Astra G is located under the upper right corner of the engine protection cover

Some more examples:

EGR valve on BMW E38

EGR valve for Ford Focus

EGR valve for Opel Omega

What is an EGR valve and types of its designs

A certain amount of exhaust gases is sent through the EGR valve to the intake manifold. Then they are mixed with air and fuel, after which they enter the engine cylinders along with the fuel mixture. The amount of gases is determined by a computer program embedded in the ECU. Sensors provide information for making decisions by the computer. Usually this is a coolant temperature sensor, an absolute pressure sensor, an air mass meter, a throttle position sensor, an intake manifold air temperature sensor, and others.

The EGR system and valve do not work continuously. So, they are not used when:

idle speed (on a warm engine);
cold engine;
fully open damper.

The first units used were pneumomechanical, that is, they were controlled using the vacuum of the intake manifold. However, over time they became electro-pneumatic and (standards EURO 2 and EURO 3) and completely electronic(EURO 4 and EURO 5 standards).

Types of EGR valves

If your vehicle has an electronic EGR system, it is controlled by an ECU. There are two types of digital EGR valves- with three or two holes. They are opened and closed by operating solenoids. The device with three holes has seven recirculation levels, the device with two - three levels. The most perfect valve is the one whose opening level is performed using a stepper motor. It provides smooth regulation of the gas flow. Some modern EGR systems have their own gas cooling unit. They further reduce the level of waste nitrogen oxide.

The main causes of system malfunction and their consequences

Depressurization of the EGR valve- the most common malfunction of the USR system. As a result, an uncontrolled intake manifold occurs. If your car has an engine with, this can lead to a lean fuel mixture. And when there is an air flow pressure sensor in the car, the fuel mixture will be re-enriched, due to which the pressure on the intake manifold will increase. If the engine has both of these sensors, then at idle it will receive a too rich fuel mixture, and in other operating modes - a lean one.

Dirty valve is the second common problem. What to do with it and how to clean it, we will analyze it below. Note that the slightest engine malfunction can theoretically lead to a significant potential for contamination.

All malfunctions occur for one of the following reasons:

Too much exhaust gas flows through the valve;
too little exhaust gas passes through it;
there was a depressurization of the valve body.

Exhaust gas recirculation malfunction can be caused by breakage of the following parts:

external branch pipes for supplying exhaust gases;
EGR valve;
thermal valve connecting the vacuum source and the EGR valve;
solenoids that are controlled by the ECU;
exhaust gas pressure converters.

EGR valve malfunction symptoms

There are a number of signs indicating that problems are observed in the operation of the EGR valve. The main ones are:

unstable engine idling;
frequent engine shutdown;
misfiring;
jerky movement of the car;
a decrease in vacuum at the intake manifold and, as a consequence, the operation of the engine on a rich fuel mixture;
often in the event of a serious malfunction in the operation of the exhaust gas recirculation valve - the car's electronic system signals a check light.

When diagnosing, error codes such as:

P1403 - malfunction of the exhaust gas recirculation valve;
P0400 - error in the exhaust gas recirculation system;
P0401 - inefficiency of the exhaust gas recirculation system;
P0403 - wire breakage inside the control valve of the exhaust gas recirculation system;
P0404 - malfunction of the EGR control valve;
- too lean fuel mixture.

How to check the EGR valve?

When checking, it is necessary to carry out inspection of the condition of the tubes, electrical wires, connectors and other components. If your machine has a pneumatic valve, you can use vacuum pump to activate it. For detailed diagnostics use electronic equipment which will allow you to get the error code. With such a check, it is necessary to know the technical parameters of the valve in order to identify the discrepancy between the received and declared data.

The check is performed in the following sequence:

Disconnect vacuum hoses.
Blow out the device without letting air pass through it.
Disconnect the connector from the solenoid valve.
Use the wires to supply power to the device from the battery.
Blow out the valve, while air must pass through it.

When the check showed that the unit is not suitable for further operation, then the purchase and installation of a new one is required, but quite often, it is advised to simply drown the USR valve.

How to muffle the EGR valve?

If problems begin in the operation of the system or the EGR valve, then the simplest and cheapest solution will be to silence it.

It should be noted right away that one chip tuning is not enough... That is, disabling the ECU control of the valve does not solve all problems. This step only excludes system diagnostics, as a result of which the computer does not generate an error. However, the valve itself continues to operate. Therefore, in addition it is necessary to perform a mechanical exclusion of it out of engine operation.

Some automakers include special valve plugs with the car. As a rule, this is a thick steel plate (up to 3 mm thick) shaped like a device hole. If you do not have such an original plug, you can make it yourself from metal of the appropriate thickness.

As a result of installing the plug, the temperature in the cylinders rises. And this threatens the risk of cylinder head cracks.

Next, remove the EGR valve. On some car models, this also requires removing the intake manifold. In parallel with this, clean its channels from dirt. Next, find the gasket that is installed at the valve attachment point. Then replace it with the metal plug mentioned above. You can make it yourself or buy it at a car dealership.

During the assembly process, the standard gasket and the new plug are aligned at the attachment point. It is necessary to tighten the structure with bolts carefully, since factory plugs are often fragile. After that, do not forget to disconnect the vacuum hoses and put plugs in them. At the end of the process, it is necessary to perform the mentioned chip tuning, that is, to make an adjustment to the ECU firmware so that the computer does not show an error.

How to drown the USR

We jam the USR

What results will jamming the USR system lead to?

There are positive and negative sides. The positive ones include:

soot does not accumulate in the collector;
the dynamic characteristics of the car are increased;
no need to change the EGR valve;
not so frequent oil changes.

Negative sides:

if the engine has a catalyst, then it will fail faster;
the breakage indicator on the dashboard is triggered ("check" light);
an increase in fuel consumption is possible;
increased wear of the valve group (rarely).

EGR valve cleaning

Often, the EGR system can be restored by simply cleaning the device. More often than others, owners of Opel, Chevrolet Lacetti, Nissan, Peugeot cars encounter this.

The service life of various EGR systems is 70 - 100 thousand km.

At cleaning the EGR pneumatic valve necessary from carbon deposits clean the seat and stem... At cleaning the USR with a control solenoid valve, usually, the filter is being cleaned protecting the vacuum system from contamination.

To clean, you need the following tools: open-end and spanner wrenches, two carburetor cleaners (foam and spray), a Phillips screwdriver, and valve lapping paste.

EGR valve cleaning

After you have found where the EGR valve is located, you need to flip the terminals from the battery, as well as the connector from it. Next, using the key, unscrew the bolts on which the valve is held, and then we take it out. The insides of the device must be soaked with a carburetor rinse.

It is necessary to flush the channel in the manifold with a foam cleaner and a tube. The procedure must be performed within 5 ... 10 minutes. And repeat it up to 5 times.(depending on the level of pollution). At this time, the valve soaked in advance is off and ready to be disassembled. To do this, unscrew the bolts and disassemble. Then, with the help of lapping paste, we carry out the lapping of the valve.

When lapping is done, it is necessary to thoroughly wash everything, both scale and paste. Next, you need to dry everything thoroughly and collect. Also definitely worth it for tightness... This is done with kerosene, which is poured into one compartment. For 5 minutes, we wait so that the kerosene does not flow into another compartment, or on the back side, no moisture appears. If this happens, then the valve is not sealed tight. To eliminate the problem, you must repeat the above procedure. The assembly of the system is carried out upside-down.

EGR valve replacement

In some cases, in particular, when the valve fails, it is necessary to replace it. Naturally, for each car model, this procedure will have its own characteristics due to the design, however, in general terms, the algorithm will be approximately the same.

However, immediately before replacing, you need to perform several operations, in particular, those related to the ECU, reset information, so that the electronics “accept” the new device and do not generate an error. So, you need to follow these steps:

check the vacuum hoses of the exhaust gas recirculation system;
check the operability of the USR sensor and the entire system;
check the patency of the gas recirculation line;
replace the EGR sensor;
clean the valve stem from carbon deposits;
remove the fault code in the ECU and test the operation of the new device.

As for the direct replacement of the mentioned device, we will give an example of its replacement on the Volkswagen Passat B6. The work algorithm will be as follows:

Disconnect the valve head position sensor connector.
Loosen the clamps and remove the cooling hoses from the valve fittings.
Unscrew the screws (two on each side) on the fastening of the metal pipes for supplying and removing gases from / to the EGR valve.
The valve body is attached to the engine with a bracket with one power bolt and two M8 screws. Accordingly, it is necessary to unscrew them, remove the old valve, install a new one in its place and tighten the screws back.
Connect the valve to the ECU system, and then use the software (it may be different) to adapt it.

As you can see, the procedure is simple, and as a rule, on all machines it is not very difficult. If you ask for help at a service station, then the replacement procedure costs today about 4 ... 5 thousand rubles, regardless of the brand of the car. As for the price of the EGR valve itself, it fluctuates between 1,500 ... 2,000 rubles and even more (depending on the car brand).

Diesel Malfunction Symptoms

The EGR valve is installed not only on gasoline, but also on diesel engines (including turbocharged ones). And the most interesting thing in this vein is that during the operation of the mentioned device, the problems described above for a gasoline engine for a diesel engine are much more relevant. First, you need to address the differences in the operation of the device on diesel engines. So, here the valve opens at idle, providing about 50% of clean air in the intake manifold. As the number of revolutions increases, it closes and closes at full engine load. When the motor is in warm-up mode, the valve is also fully closed.

The problems are primarily related to the fact that the quality of domestic diesel fuel, to put it mildly, leaves much to be desired. During the operation of the diesel engine, contamination occurs directly on the EGR valve, the intake manifold, as well as the sensors installed in the system. This may result in one or more of the following signs of “illness”:

unstable engine operation (jerks, floating idle speed);
loss of dynamic characteristics (it accelerates poorly, shows low dynamics even in low gears);
increased fuel consumption;
decrease in power;
the engine will work more “hard” (after all, the EGR valve in diesel engines is just needed to soften the operation of the engine).

Naturally, the listed phenomena can be signs of other malfunctions, however, it is still recommended to check the mentioned unit using computer diagnostics. And if necessary, clean, replace or simply drown it.

Another way out is to clean the intake manifold and the entire corresponding system (including the intercooler). Due to low-quality diesel fuel, the entire system becomes significantly contaminated over time, therefore, the described malfunctions may be the result of just banal contamination, and will disappear after you perform the appropriate cleaning. This procedure is recommended to be done at least once every two years, and better - more often.

We considered the device of the EGR valve, how it works, gave examples of malfunctions and the reasons causing them. And today we will pay close attention to directly disconnecting the valve, why the owners go for this and, most importantly, how to turn off the USR valve with their own hands.

EGR valve l6735 Chevrolet Lacetti

Why turn off the EGR valve?

We already know that, in principle, the EGR system is designed to recirculate exhaust gases back into the intake system for mixing with gasoline or diesel. Due to recirculation, the amount of clean air is reduced, therefore the formation of various nitrogen oxides is also reduced, compared to if only pure oxygen were used.

The main element in this system is the EGR valve, which is responsible for opening the "path" for the exhaust gases at a certain moment, directing them to the intake manifold. Thus, the proportion of oxygen is reduced, and, accordingly, the combustion temperature. We must understand the root causes of the appearance of the system, this is the reduction of emissions, and they just have the greatest effect at a high combustion temperature. Therefore, the circulation of exhaust gases allows you to reduce emissions by lowering the combustion temperature.

Thus, a part of the total share of exhaust gases is transferred through the valve back to the engine (usually the system is set to rpm, after 2,000 the valve opens and releases exhaust gases), reducing emissions into the atmosphere. But, you yourself understand that the exhaust gases are "dirty", and passing through the valve, they clog it, which makes it periodically necessary to clean it. A clogged valve disrupts the mixture formation process, that is, it prevents the supply of clean air and, at the same time, does not even allow the exhaust gases to pass through in the required quantities. As a result, the mixture is too rich, more fuel is supplied than usual. The engine becomes clogged with carbon deposits, the USR valve itself is covered with carbon deposits, a film of unburned mixture appears on the cylinders, which means the rapid wear of the piston group.

And most importantly, after turning off the USR, fuel consumption is reduced. When the USR is turned off, the fuel mixture is formed better, without waste impurities, the amount of oxygen increases, which is why the fuel mixture burns more efficiently in the cylinders without leaving carbon deposits.

And besides, recently they began to openly say that, as such, the benefits of the valve are almost zero. If, during the operation of the valve, the emission of nitrogen into the atmosphere is reduced, then when it is turned off, the emission of soot, carbon dioxide and carbon monoxide is reduced.

Plus, with a dirty valve, the internal combustion engine malfunctions are observed, the power is reduced,. As you can see, there are many more real reasons to disable this system.

That is, the following group of reasons can be distinguished in which cases they decide to muffle the EGR valve:

The valve is dirty, there is no desire to clean it or buy a new one.

Problems with sensors on which the mixture formation depends.

Rapid wear of the cylinder-piston group.

Increased fuel consumption.

Reducing the power of the internal combustion engine.

ICE operation.

It is worth noting that all these reasons in most cases appear after the valve fails or becomes dirty. And its diagnostics, replacement, repair, cleaning is a rather expensive undertaking, so the most attractive domestic drivers see a banal blocking of the operation of this system in whole or in part.

How to turn off the EGR valve?

First you need to understand that in addition to the mechanical part of the USR system, there is also an electronic one, which sends indicators to the ECU, affecting the formation of the fuel mixture. Accordingly, for the correct shutdown of the valve, you need to use:

Electronic jamming.

Mechanical intervention.

But, not always the owners apply, both options. Rather, on the contrary, in the process of jamming, they resort to the least costly and complex, namely mechanical blocking. So, options for disabling the EGR valve:

1. The most banal thing that every driver can do is simply to "throw off" the chip from the valve. But, there is a drawback, on almost all machines after such manipulations the "check" is constantly lit. It is not so easy to throw it off, so in the event of any really malfunction, the driver is unlikely to know about it in advance. Not the best way to turn off.

2. Replacing the valve gasket. At the valve attachment point in the intake manifold, there is a gasket with intake holes, etc. What do you need to do? Cut out a similar gasket according to the template, completely "blind" without any holes. Naturally, do not forget about the mount.

Any material can be used, even aluminum, brass, stainless steel. But, keep in mind that the exposure temperature will always be high, so it is better to select the appropriate thickness immediately so that the gasket will last longer.

USR valve plug installed

In some cars, the plug also causes errors in the ECU, respectively, "" will light up. Remember this.

3. Many car owners generally act "barbarously", in the channel where the EGR valve is located, they tighten the usual bolt with the desired thread, if necessary, the thread is even cut.

4. Installation of a plug not only after the valve, but also before it. Since, installing metal plates, removing the chip, the exhaust gases will still get on the valve, contaminate it and disrupt the operation of the internal combustion engine. To get rid of this, it is necessary to close the channel for the intake of exhaust gases from the exhaust manifold to the intake. There are usually simple hoses twisted onto a nut, like plumbing. On many machines, instead of attaching the hose to the valve, either a coin or a metal circle is inserted in shape and size. Thus, blocking the flow of gases from the exhaust manifold.

5. The most effective and efficient way, it includes software shutdown of the EGR valve through the ECU. In this case, the "check" will not light up due to a violation of the circulation. In all of these cases, "check" would definitely "jump out". But, with the introduction of amendments to the "brains", you can solve this problem. But, you need to have experience, knowledge, equipment, which can not be found in every service.

Software jamming involves removing the EGR valve firmware from the ECU. That is, with the help of a computer and a special program for this. As a rule, large service stations have craftsmen specializing in this topic. By switching off the valve by software, there is not even a need for mechanical jamming. After that, many do not even disconnect the chips and drive with a valve. Indeed, by and large, the "brains" no longer give the command to open / close the valve and there is no need to dismantle it. But, others advise to do physical jamming in pairs, in one of the ways listed above.

Conclusion

As a result, I would like to emphasize that in our country it is still possible to turn off this valve without consequences. Large-scale industries do much more harm, so you can calm your own conscience. Moreover, disabling this system allows not only to reduce consumption, increase engine power, but also increase the resource not only of the internal combustion engine itself, but also of various sensors that depend on it.

There are a lot of options for switching off, the main thing is to understand that with mechanical intervention, it will not be possible to turn off the electronics, which is why the constantly burning "check" will cause inconvenience. A really effective way to turn off this system completely, to make changes in the "brains", the main thing is to find a good master.

Developers of modern cars are constantly improving engines to improve their environmental component. The USR system is one of the mechanisms allowing to minimize toxic emissions into the atmosphere by returning part of the exhaust gases to the combustion chamber, while the operation of the diesel engine becomes "softer". When operating a power unit with EGR, many car owners are faced with breakdowns or malfunctions in the recirculation system. A new part for replacement is quite expensive, but it is quite amenable to cleaning, repair, or the system simply turns off.

How does the USR work on a turbodiesel

The main function of the EGR system is to partially return the exhaust gas to the intake manifold for afterburning. On a diesel engine, this solution allows for a softer and smoother engine operation, which improves its performance and reduces fuel consumption, and the exhaust reduces its toxicity. The appearance of exhaust gases in the intake does not change the ratio of the main components of the combustible mixture, power is not lost in different operating modes, and fuel is saved.

The principle of operation of the EGR valve on diesel engines is the connection of a part of the exhaust gases with the air entering through the intake manifold. The engine exhaust contains nitrogen oxides due to the increased heating of gases in the combustion chamber. By activating the EGR system, combustion occurs at a lower temperature, and the level of harmful substances in the exhaust becomes less. On diesel engines, the valve opens automatically at idle speed, and closes at load and maximum power.

Why the EGR valve is muffled

With prolonged operation of a diesel engine equipped with an EGR system, car owners often feel a decrease in power and the appearance of exhaust smoke. Engine tuning enthusiasts argue that gas recirculation chokes the powertrain, preventing it from showing its full power potential. Based on such arguments, many drivers decide to drown out the USR system. A similar procedure is to turn off the recirculation system, which theoretically should add power.

It is believed that the rapid formation of carbon deposits on the EGR valve and the intake of exhaust gases into the intake manifold provoke increased carbon formation and coking of the combustion chamber. A malfunction of the USR system associated with the failure of the valve leads to excessive fuel consumption and unstable engine operation. Resins and soot enter the combustion chamber, due to which the diesel oil is quickly oxidized, and the total engine life of the power unit decreases.

The need to turn off the USR appears with a mileage of 80-120 thousand km, because the presence of such a mileage causes certain engine wear. Exhaust gases redirected inward are highly contaminated. After their further mixing with crankcase gases, a thick layer of tarry deposits appears in the intake manifold, EGR valve and engine head valves. A clogged system causes errors and can provoke an abrupt transition of the car to emergency mode.

EGR malfunctions on diesel

The EGR valve is a part that performs a bypass function, which either passes a part of the exhaust gases from the manifold to the supply line, where they mix with air (in case of serviceability), or not. In the event of a valve malfunction, the ECU will issue a corresponding error on the dashboard indicator. Failures of the USR on a diesel engine can be as follows:

Carbon deposits in the system that affect the valve and EGR plate. Excessive soot formation occurs when the engine is operated on low-quality fuel, with incomplete combustion of the fuel mixture, and a violation of the crankcase exhaust system.
Clogging of the valve, in which it becomes jammed when opening or closing, or incorrect operation in the form of untimely operation, which is noticeable when the engine is idling.

Failures of the USR are manifested in frequent stopping of the engine, floating rpm in idle mode, triplet, jerking during movement and a drop in power during acceleration.

It is possible to identify a breakdown of the recirculation system by visual inspection of the condition of pipelines and sensor connectors. Accurate diagnostics include electronic scans and other procedures that check the functioning of the actuators and the EGR valve.

Repair of USR on diesel

Repair of the EGR system consists in its mechanical cleaning from carbon deposits and deposits using a small metal brush and flushing with the "WD" cleaner, which is designed to remove deposits and rust from metal. At the end of the procedure, the inside of the valve is wiped with a cloth soaked in solvent. The repair of the USR on a diesel engine also includes cleaning the solenoid (if any), which acts as a filter element that prevents debris from entering the vacuum system.

The USR valve is flushed from burning after it has been removed, processed through the holes with a special aerosol used to clean the carburetors, then the part is placed in a container filled with lighting kerosene. Then they are disassembled by unscrewing 4 bolts and cleaned from the inside. This service will eliminate the symptoms of a malfunctioning EGR valve and restore it to proper operation. The procedure should be carried out regularly after 60-100 thousand kilometers.

How to properly muffle the EGR valve on a diesel engine

Correctly disabling EGR on a diesel engine assumes:

Mechanical way of dampening the valve.
Shutdown by means of the control unit.

At the first stage, a mechanical valve plug is installed, after which the system is turned off on the electronic equipment. You should be aware that just physically muffling the valve is enough only on some cars. After mechanical blocking of the valve, its software must be disabled in the ECU, otherwise the "check" lamp will light up on the instrument panel due to an error in the recirculation system, and the engine activates emergency mode, in which the power output is limited.

The simplest version of the valve plug is as follows:

The valve, which is most often located near the intake manifold, is removed by unscrewing a few bolts.
If necessary, dismantle the intake manifold and clean its channels from contamination.
Remove the gasket located at the valve attachment point.
The removed gasket is used as a template, according to which a blanking gasket is cut out of the steel sheet, and holes are made in it for bolts. Often, a plug for some car models can be found on sale.
Reinstalling the valve using a gasket and plug. The bolts are tightened with extreme care due to their fragility.
Disconnect the vacuum hoses, since they are no longer used in the valve opening system.
Making changes to ECU firmware to get rid of EGR error.