The Exhaust Gas Recirculation system (EGR) is a solution that reduces the level of nitrogen oxides in the exhaust gases of a gasoline or diesel engine. This system, as applied to modern internal combustion engines, is absent only on gasoline turbo engines.
Diesel engines have different emission standards. For this reason, EGR of a diesel engine can be implemented according to various schemes. The USR exhaust gas recirculation system of a diesel engine can be:
- high pressure system;
- Low pressure USR;
- combined EGR system;
We also recommend reading the article about the features of operating a diesel engine in winter. From this article you will learn about additives in diesel fuel, glow plugs, heating diesel fuel, as well as preventive measures for confident starting of a diesel engine at subzero temperatures.
That's why you need to take the EGR valve seriously: it's small and clever.
If the EGR valve stops working correctly, then certain symptoms may appear in the car, clearly indicating to us that the exhaust gas recirculation system is faulty. Fortunately for you and me, most often this does not mean that it is time to change the valve itself. In many cases, we can easily fix everything ourselves.
Exhaust gas recirculation in diesel and gasoline engines
At first glance, it may seem a little strange to us that the engine exhaust gases do not always and immediately exit completely through the exhaust pipe. In fact, these waste gases are returned back to the engine. This technical trick lowers the combustion temperature of diesel fuel, which subsequently reduces the formation of harmful substances such as nitrogen oxide (NOx). Recirculated exhaust gases displace fresh air in the intake duct, i.e. those low oxygen levels in the exhaust gases then absorb some of the heat of combustion in the combustion chamber, resulting in a significantly reduced combustion temperature. As a result, the formation of harmful nitrogen oxide drops sharply.
This EGR valve is controlled by vacuum.
When the valve (inside) opens, it clears the way for exhaust gases to enter the intake duct. See also: New law on control over technical inspection from January 1, 2022
Gasoline engines also use an exhaust gas recirculation system. Here, the return of exhaust gases to the engine serves to reduce the fuel consumption of the vehicle, since the throttle valve can be further opened due to pressure from the returned exhaust gases. In this way, the so-called energy losses when opening the throttle valve are reduced, and this helps to reduce fuel consumption and, accordingly, leads to a decrease in the level of harmful substances in the exhaust system itself.
Principle of operation
The USR valve, the operating principle of which is to partially send gases back to the manifold, operates according to a simple algorithm. After entering the manifold, it is mixed with air, and after that the cylinders receive a mixture with a small proportion of oxygen. This leads to a decrease in combustion t in the cylinders. It turns out that the mixture burns, thereby greatly reducing the formation of nitrogen oxides harmful to people.
The valve performs the main job of improving the environmental situation. It is the connecting link between the intake and exhaust manifolds. The amount and time of release of the mixture is determined by the computer. The electronic unit works in conjunction with various types of sensors.
By the way, the system does not work all the time; it is started by a signal from the ECU. The USR will not turn on if the engine speed is less than 900 units per minute. Also, it will not work if the number of revolutions exceeds 4000 per minute. Starting occurs when the engine warms up to 60 °C at idle.
Internal and external exhaust gas recirculation
Internal combustion engines (ICEs), as a rule, have two exhaust gas recirculation systems, i.e. – internal and external. The internal engine exhaust gas recirculation system does not require additional components, as it is implemented by the design of the power unit itself. Thus, during engine design, engineers adjust the timing of the valves so that they remain open for some time at the beginning of the intake stroke. As a result, some of the previously released exhaust gases are sucked back into the combustion chamber.
With external exhaust gas recirculation, the exhaust gases are directed into the intake channel through the external exhaust gas system pipeline (EGR-EGR system). Many diesel and some gasoline engines use an EGR aftercooler. This cooler cools the exhaust gases using antifreeze (coolant), which significantly lowers the temperature of the exhaust gases, leading not only to a decrease in fuel consumption, but also to a significant reduction in the level of harmful substances in the exhaust system of the car itself (the combustion temperature decreases).
What is a car exhaust system
How to boost a naturally aspirated engine
If you look at the statistics, most car owners have cars with engines up to two liters. At the same time, the power of the cars does not exceed 120 horsepower. It is this fact that makes many car enthusiasts pay attention to the possibility of increasing power. Moreover, if you know the displacement of engines in Formula 1 cars with a power of 600 horsepower with a displacement of 1.6 liters, or pay attention to the modern developments of other engines of comparable displacement. Therefore, most car enthusiasts will be interested in knowing what exactly allows small-displacement engines to develop such power, and how to independently achieve this on a conventional naturally-aspirated engine. What is car engine power? To fully understand the improvements, it is necessary to understand the theoretical issues of internal combustion engine power. But we will not go deeper into the topic, but will consider only brief principles and the essence itself. To begin with, you need to understand the main concept that power is torque multiplied by the number of crankshaft revolutions per minute with a coefficient. (adsbygoogle = window.adsbygoogle || []).push({}); In fact, the result of such calculations will be a certain number expressing work per unit of time, but operating with this formula is easier than calculating horsepower. From the above formula, the only conclusion appears is that in order to increase engine power, it is necessary to increase the torque or engine revolutions per minute. There is nothing difficult to understand, but the difficulty lies in the methods and consequences of increasing the speed or torque. It would seem, why can’t you increase the crankshaft speed to 9,000-10,000, instead of 5 or 6 thousand? The fact is that each engine has its own strength limits, and increasing speed increases the load on the engine in a quadratic progression. Therefore, it is impossible to increase the speed without major changes in the engine design. Naturally, when boosting the engine yourself, there is no way to adapt the motor to high speeds, and you have to increase the torque. What is torque? Having decided to increase the torque, the car owner will also be faced with the problem of increasing the load on the engine, but in a linear progression. Therefore, it becomes possible to carefully raise it to an acceptable level. To do this, you need to increase the amount of fuel mixture in the combustion chamber. At the same time, fuel consumption increases and the need for more air. Only with efficient combustion of all gasoline can high performance be achieved from the engine. But it is known that in order to burn a kilogram of gasoline, up to 15 kg of air is needed, which will be about 12 cubic meters per 1.4 liters of fuel. Therefore, the question remains of increasing the amount of air, because increasing the volume of supplied fuel is not so difficult. Based on the information written above, it follows that it is necessary to install a turbine or compressor on your engine, or increase the volume of the combustion chamber. This is what will allow you to add torque to the car, and, accordingly, power. Dependence of torque on working volume It is worth dwelling on this point in more detail; the rule fully applies to an atmospheric engine: “per 1 liter of working volume, there is from 85 to 120 Nm of torque.” This rule has persisted for many decades, and even modern technology is not able to overcome it. Only engines of very old modifications stand out from the crowd, and not for the better. For example, the VAZ engine, which was installed on a “penny”. It had a working volume of 1.2 liters, with a torque of 87 Nm. But this is an outdated power unit with inefficient ignition and a carburetor fuel injection system. And a modern engine with the same displacement installed in the Skoda Fabia is capable of developing up to 112 Nm. And the popular 1.8-liter engine from Toyota develops up to 170 Nm of torque. At the same time, the German M111 engine with a displacement of 2.3 liters has 220 Nm, the M272 with three liters develops up to 300 Nm of torque. In principle, there are no serious exceptions to this rule; even the most advanced naturally aspirated engines installed on Formula 1 cars, which had a volume of 2.4 liters, did not develop more than 260 Nm of torque, but due to high revolutions per minute (up to 17,000 - 18,000), had enormous power. This is due to the fact that torque depends on the degree of filling of the combustion chamber, and in a non-turbocharged engine, it depends entirely on atmospheric air pressure. Therefore, without increasing the displacement and modifying the engine, it is very difficult to increase torque. Of course, you can achieve a positive result by improving the intake and exhaust system, but the increase compared to the invested funds will be insignificant. The situation with turbocharged engines looks completely different. Thanks to a turbine or compressor, any required amount of air can be forced into the combustion chamber. For example, the EA111 power unit installed on the Skoda Octavia has a displacement of 1.4 liters with 250 Nm of torque. Therefore, the limitation in turbocharged engines is only the strength of the components that must withstand increasing loads. From this, the only conclusion follows - without a turbine or compressor, it is impossible to increase the torque by an order of magnitude. Even serious and full-scale modifications to the power unit will lead to a slight increase in torque per liter of volume. But if you remain a strict adherent of naturally aspirated units, then we will next try to talk about possible actions to boost the engine, and ways to achieve maximum performance from the engine. Reworking the engine when boosting You shouldn’t relax and think that you can increase power on a naturally aspirated engine without much hassle. Moreover, if you want to take the path of increasing maximum speed (the most effective way to increase engine power), you will have to change the piston group to a lighter and stronger one, which can cost a significant amount. And so, for a comprehensive rework of the engine, you will need to purchase a forged and lightweight crankshaft, the same H-shaped connecting rods, T-shaped forged pistons with a reduced height and, of course, new connecting rod bolts with increased strength. Also, it is worth taking care of a new oil pump with increased performance, for greater efficiency at higher speeds. Special pistons can be purchased that are used for extreme engine power increases and are designed to use just two piston rings to reduce friction losses, with minimal thickness to reduce weight. Do not think that all changes have ended at this stage. In addition to the piston group, the gas distribution system will have to be modified to match the increased speed. In order for the valves to close and open on time at higher speeds, the valves themselves will have to be lightened using new materials, and special springs with greater elasticity will have to be purchased. Also, you will have to install new camshafts, allowing you to open and close the valves faster. And the increased load on all components requires the use of expensive materials and high precision production, which leads to the high cost of all components. Next, there remains the modification of the intake and exhaust systems. To do this, new manifolds with a thoughtful shape are installed to reduce resistance and the channels in the cylinder head are carefully polished. Examples of engine modifications by professionals and modification kits Next, we will look at examples of tuning atmospheric engines using the example of professional teams and proven engines. For example, the Opel C20XE engine, which was specially created for the possibility of further modification. It has earned popularity among many racing teams, including Opel. Chevrolet and Lada. Moreover, it was used for two decades. This speaks to the extreme reliability and efficiency of this unit. Opel C20XE It’s worth taking a little break from tuning and giving a little explanation. This article is not intended to provide step-by-step instructions for converting motors, since each specific case requires an individual approach. Here, we are trying to explain the principles of forcing, and explain what is being done and why. Therefore, below we will show prices for kits from tuning studios that developed and tested their parts, and did not do everything “on the knee”. Also, it is worth considering that this power unit has a good margin of safety, which makes its modification somewhat cheaper. Therefore, high-quality rework of mass-produced or inexpensive units can be more expensive. When released from the factory, the engine from the Opel C20XE has a displacement of two liters and a maximum power of up to 150 horsepower. The long-term use of the engine as the main power unit for participation in various racing competitions has allowed many companies to gain extensive experience in its modification. Therefore, it is possible to purchase ready-made tuning kits that will give an already known result without the risk of breakdown. But the engine must be in working condition and not on the verge of being scrapped. Each of the kits differs in price, configuration and final power. For example, the cheapest kit from the famous company Qedmotorsport will cost 129,000 rubles at the current ruble to pound exchange rate. Not cheap? But the entire set is time-tested and worked out to the smallest detail. The kit included a modified intake manifold with a throttle valve for each cylinder, a modified fuel rail with increased capacity and pressure regulator, an updated electronic powertrain control unit, new wiring and a two-stage maximum crankshaft speed limiter. Also, you will have to install new camshafts and new connecting rod bolts with increased strength. This will give a power increase of up to 190 horsepower with a guarantee of reliability. If the new power is not enough for the car owner, then you can purchase a more expensive kit and achieve power of up to 210 horsepower. To do this, you will have to shell out 36,000 rubles more. This kit will additionally include lightweight but more durable pistons, special timing gears with the ability to fine-tune the phases and other camshafts to speed up valve operation. In order for the engine to operate at a power of 220 horsepower, you will need to pay another 18,000 rubles, or 183,000 in total. At the same time, the buyer will receive a set of spare parts for modifying the valves and the entire gas distribution system. The kit will include camshafts made to work without hydraulic lifters, different valve springs and updated lifters. The top-end kit for this engine will allow you to develop up to 245 horsepower, but you will have to spend 197,000 rubles. At the same time, it will not differ in anything from the previous one, except for settings for higher speeds and loads. At the same time, a modified engine up to 250 - 260 horsepower, and having a certificate of passing inspection at a special stand, can cost from 250,000 rubles to 360,000 rubles. These prices do not include taxes and delivery costs. It is worth noting that the engine of this model could develop a power of 320 horsepower, when modified by factory teams with an unlimited budget and any test benches for testing. The same situation applies to another engine that has proven itself in rally racing - this is the Duratec with a displacement of 2 liters and a power of 150 horsepower. The technical characteristics are very similar to the previous motor, but it has a more modern design. Duratec For example, we will take the development of one of the companies Omex Technology Systems, which independently modifies motors and sells them in a forced version. The initial kit will increase engine power to 180 horsepower, thanks to a modified intake manifold with separate throttle valves for each cylinder, an updated electronic control unit, “aggressive” camshafts, connecting rod bolts made of high-strength alloys and a new exhaust system. This will allow the car to withstand up to 7.8 thousand crankshaft revolutions, and the declared power of the unit is achieved at 6,500 rpm. But the cost of a forced engine will be 430,000 rubles. The power unit, modified to 200 horsepower, will cost 494,000 rubles. At the same time, the engine will have a modified cylinder head and combustion chamber, and the declared power is achieved at 7,000 crankshaft revolutions. For the maximum power of this engine, you will have to pay 830,000 rubles. In this case, the engine will receive 260 horsepower, thanks to a new set of forged piston group, strengthening and lightening of the gas distribution mechanism, increased performance of the fuel system and other modifications. At the same time, the maximum crankshaft speed is increased to 8,700 rpm, and maximum power is achieved at 8,500 rpm. From these examples it is clear that boosting a naturally aspirated engine is an expensive procedure with minimal improvements in technical characteristics. Conclusion Now it has become clear that when tuning a naturally aspirated engine, it is more profitable to raise the maximum speed limit. An even better effect will be obtained by reducing the drop in torque at maximum speed, or increasing it. In this case, you can achieve up to a 40% increase in power, but the cost of such tuning will exceed all imaginable limits. Therefore, it is best to boost the engine using a turbine or compressor. In this case, you can get a more acceptable option with less money spent. Author of the article: Dmitry GotovchikView news
Function of the EGR (exhaust gas) valve
When and in what quantities exhaust gases are sent to the external gas recirculation system is regulated and controlled through the exhaust gas recirculation valve - often called the exhaust gas recirculation (EGR) valve - or EGR.
The EGR valve usually consists of a poppet valve or a special gate valve. This valve releases or prevents the movement of exhaust gases into the engine intake tract.
Using sensors such as the mass air flow sensor and the oxygen sensor (lambda probe), the engine control unit calculates the ideal amount of exhaust gas recirculation and accordingly controls the exhaust gas recirculation valve (EGR valve).
The mechanical movement of the EGR valve device is usually performed electro-pneumatically or electrically using a servomotor.
On some vehicle models, the EGR valve is also equipped with a position sensor that monitors the correct opening and closing of the flap or pushrod. By the way, exhaust gas recirculation occurs only in the part-load region of the engine.
EGR valve - defects and symptoms
Often the exhaust gas valve (EGR) is coated with a mixture of soot and oil.
In the photo, friends, you can see what the exhaust gas recirculation valve looks like after thousands of kilometers of vehicle operation. A faulty EGR valve can manifest itself in different ways. Here are signs that may indicate a faulty EGR valve:
— When accelerating, the car picks up speed jerkily.
— Fluctuations at idle.
— Loss of engine power.
— The “Check Engine” icon appears on the dashboard (Check Engine – emergency engine operation program).
— The level of nitrogen oxide in the exhaust gases increases.
— Black smoke from the exhaust pipe.
— Increased fuel consumption.
Since the EGR valve and its control mechanism are located in the exhaust gas stream, it is the most sensitive component of the exhaust gas recirculation system. Due to the soot contained in the exhaust gases, the control mechanism of the exhaust gas recirculation valve may begin to operate incorrectly over time - the valve may no longer open or close normally.
This valve can also become dirty due to oil vapors from the oil separator, which, in combination with soot, do their evil work over time.
As a result of improper operation of the exhaust valve, the level of harmful substances in the exhaust system can significantly increase. There may also be a delayed response from the car when you press the gas pedal (throttle response). The most common symptom of a faulty exhaust valve is a severe loss of engine power. This usually happens when the valve fails to close properly. Along with the loss of power in this case, black smoke may also appear in the exhaust pipe, which is formed due to the lack of the necessary portion of fresh air at full load.
See also: Everything you need to know when using AdBlue in your car
If the EGR valve is stuck in the closed position, then it is possible that when driving the car you simply will not notice any signs of its malfunction. But if you take and measure the level of nitrogen oxide during this type of malfunction, you will immediately discover that it is significantly higher than the norm.
In particular, a dirty exhaust valve (which also inevitably means contamination in the engine intake system) can also lead to increased fuel consumption. By the way, sometimes all these signs can appear only periodically (not constantly), since the USR valve can restore its function on its own. However, even temporary symptoms of instability should not be ignored, since this clearly indicates its malfunction. Which means that in the near future, problems with the exhaust valve will become more frequent and sooner or later this will lead to failure of this valve.
USR malfunctions on diesel engines
The USR valve is a part that performs a bypass function, which either passes part of the exhaust gases from the manifold into the supply line, where they are mixed with air (if in good condition), or not. If the valve malfunctions, the ECU will display a corresponding error on the dashboard indicator. Malfunctions of the USR on a diesel engine may include the following:
- Carbon deposits in the system that affect the EGR valve and plate. Excessive carbon formation occurs when the engine is operated on low-quality fuel, incomplete combustion of the fuel mixture, or a violation of the crankcase gas exhaust system.
- The valve is clogged, causing it to jam when opening or closing, or incorrect operation in the form of untimely operation, which is noticeable when the engine is idling.
USR malfunctions manifest themselves in frequent engine stops, floating speed in idle mode, tripping, jerking while driving and a drop in power during acceleration.
It is possible to identify a breakdown of the recirculation system by visually inspecting the condition of the pipelines and sensor connectors. Accurate diagnostics include electronic scanning and other procedures that check the functioning of the actuators and the EGR valve.
Because of the exhaust gas valve, the “Check Engine” light is on on the dashboard.
Another sign of a malfunctioning EGR valve is the appearance of an engine error (“Check Engine”) on the instrument panel. True, such an appearance of an engine error is not necessarily associated with the exhaust gas recirculation valve position sensor, which usually detects an incorrect valve position in some cars.
A malfunction in the exhaust valve can also be detected by other vehicle sensors, such as pressure or temperature sensors, which can transmit conflicting values (data) to the engine control unit due to the lack of exhaust gases in the exhaust gas recirculation system. As a result, we observe that if the sensors detect a malfunction in the engine, then the “Check Engine” warning lamp lights up on the vehicle’s instrument cluster.
Also, the error code itself is recorded in the memory of the engine control unit itself, which led to the appearance of the “Check Engine” icon.
So, in the computer memory, when the “Check Engine” icon appears, due to improper operation of the exhaust gas valve, an error code may appear that means “Exhaust gas recirculation is too low.”
The following error may also appear, meaning “Leak in the intake system.” This error may appear when the valve is stuck in the open position. However, friends, please note the following: sometimes error codes related to exhaust gases can mean completely different engine malfunctions that are in no way related to defects in the EGR valve.
System classification
The modern valve has different formats. Each of them has its own appearance, operating principle and drive method.
Electronic systems are considered the most popular, since they are installed in cars manufactured after 2010. The equipment works smoothly, the valve is open and closed. Control occurs through the on-board computer through pulses supplied to the engine. The accuracy of the system is increased due to the fact that the valve can partially open the tract.
Electropneumatic systems receive signals from the on-board computer. In other words, it commands a valve that operates in only two positions (unlike an electronic system). It either turns on or off the vacuum source to the EGR valve. Control is organized based on various sensors, including exhaust gas pressure and vehicle speed. But it is not a fact that all sensors will control. Different manufacturers develop different operating algorithms. Since electropneumatics are practically not prone to coking, their service life is low. Unfortunately, the gaps often become clogged with dirt. In this case, cleaning will not help, because... a complete replacement of the mechanism is required.
Pneumo-mechanical systems are considered obsolete today, but simple. They are controlled through the creation of a vacuum in the manifold (intake). If problems arise, they can be eliminated by cleaning the device.
Is it possible to drive a car with a faulty EGR valve?
Short-term symptoms of a bad EGR valve are usually nothing to worry about. But still, if, due to the operation of the exhaust valve, the “Check Engine” icon appears on the dashboard and the engine goes into emergency operation, then you need to contact a technical center as soon as possible for computer diagnostics of the entire system, and also get advice from a car mechanic.
See also: Camshaft: Damage, symptoms, costs
If during the diagnostic process it turns out that the EGR valve is stuck in the open position (usually recognized by a loss of power at full engine load), this can lead to a constant supply of exhaust gases into the intake system itself. As a result, exhaust gas recirculation itself increases beyond partial engine load, which leads to incorrect fuel injection. Thus, when the engine is fully loaded, incomplete combustion of fuel occurs. This in turn leads to excessive soot formation, which, for example, in a diesel engine can clog the particulate filter. In the worst case scenario, a faulty EGR valve that is stuck open can lead to turbocharger (turbine) failure.
Symptoms of a problem
Having figured out how the EGR valve works, we advise you to carefully consider the signs of its malfunction. In the previous paragraph, the problems were partially described. Failure to operate is accompanied by valve clogging. This provokes jamming, which leads to an increase in the response period.
Jamming reduces engine power. Diesel models produce black smoke. A noticeable reduction in power also occurs when the valve is constantly open. Problems are indicated by the appearance of the “CHECK ENGINE” icon on the instrument panel.
In vehicles manufactured before 2000 and with high mileage, valve failure is not accompanied by anything. For this reason, drivers should independently check its performance during the changing seasons. The motorist should inspect the wiring, windings and conduct computer diagnostics.
Causes of a faulty EGR valve
If the EGR valve is dirty, the most common malfunction is the valve mechanism getting stuck in the open or closed position. And this is a completely natural process. After all, the exhaust valve mechanism is located in the unfiltered exhaust gas flow, and this will inevitably sooner or later lead to its failure. Typically, the exhaust gas valve has a fairly long service life. This is especially true for older cars. But what is interesting is that in more modern cars this EGR valve fails much faster. For example, in the past, on cars, the exhaust valve could work for decades and easily serve for at least 200 thousand kilometers. But modern cars today have already received new software, which is configured for lower levels of harmful substances in the exhaust system (due to the new, stricter environmental standards recently adopted by the EU).
As a result, software in new cars helps speed up exhaust gas recirculation. This is done to specifically reduce nitrogen oxide emissions. So, friends, remember that in modern cars the resource of the exhaust valve has become significantly less than it was in old cars.
In addition, faulty electrical line plug contacts can also lead to malfunction of the EGR valve. Also, the cause of improper operation of the exhaust gas valve can sometimes be damage to the external exhaust gas recirculation line. So, for example, the exhaust gas recirculation system pipe may simply become damaged and small cracks may appear in it. Rubber seals may also be damaged, which will certainly lead to exhaust gas leakage. Eventually, the EGR system will start to malfunction.
Another common exhaust valve malfunction is related to oil loss in the engine head area. In this case, oil vapors resulting from combustion may lead to contamination of the EGR valve.
In this case, cleaning the old contaminated exhaust valve or replacing it with a new one is only advisable if the cause of the oil vapor has been eliminated. Do not forget about vacuum hoses, which, if damaged, can lead to improper operation of the exhaust gas valve. The fact is that due to damage to the hoses, a vacuum leak will occur, which will lead to interference with the opening of the EGR valve.
Finally, a malfunction of the exhaust valve can be caused by a broken mass air flow sensor.
Preventive measures
A diesel engine operates smoothly when a recirculation system is installed. But many drivers tend to remove the valve by closing the hole with a gasket and reflashing the software. In some cases, such an approach takes place. But drastic interventions often cause t in the cylinders to increase, which leads to detonation or the appearance of cracks in the cylinder head. There is no point in talking about a decrease in environmental indicators. Gases enter the atmosphere and harm it.
To avoid all these problems, it is necessary to clean the valve periodically. This is the only recommendation that provides reliable prevention of problems with the EGR valve. There is no need to wait until the system fails completely and you have to spend money on restoring it. Experts advise contacting professionals at the first suspicion of a device malfunction.
Cleaning the EGR valve
If there is a suspicion of a malfunction of the exhaust gas recirculation valve, it should be checked first for possible contamination. If heavy soot deposits are found inside the valve, this will clearly indicate a possible cause of malfunction of the EGR valve. Fortunately for you and me, in most cases you can clean the valve and return it to functionality yourself.
Here is the EGR valve on a Lexus IS 220d.
To get to the exhaust valve to clean it, just remove the decorative cover on top of the engine and you're done. See also: How does exhaust back pressure affect car power?
To do this, you need to use a cleaning spray designed specifically for cleaning EGR valves and the entire engine intake system. As a rule, such cleaners are sprayed onto the exhaust gas recirculation valve and quite easily clean it of dirt and soot. Most often, exhaust valve cleaner is sprayed into the engine intake tract while the engine is running (observe the manufacturer's instructions!) using a hose. Thorough cleaning of the engine valve and intake system will usually resolve EGR malfunctions.
USR repair on diesel
Repair of the EGR system consists of mechanically cleaning it from carbon deposits and deposits using a small metal brush and rinsing with a “WD” cleaner, which is designed to remove deposits and rust from metal. At the end of the procedure, wipe the inside of the valve with a rag soaked in solvent. Repairing the USR on a diesel engine also includes cleaning the solenoid (if there is one), which serves as a filter element that prevents debris from entering the vacuum system.
Flushing the USR valve from burning is carried out after removing it, treating it through the holes with a special aerosol used to clean carburetors, then the part is placed in a container filled with lighting kerosene. Then they disassemble it by unscrewing 4 bolts and clean it from the inside. This service will eliminate signs of EGR valve failure and restore it to proper operation. The procedure should be carried out regularly after 60-100 thousand kilometers.
Replace the EGR valve or clean it - Which is better?
On some engines the EGR valve is easily accessible. But on many cars, in order to get to the exhaust valve, it is necessary to disassemble half the engine. In this case, just removing the valve will cost you a pretty penny. Especially if there is a defect in the valve and you have no choice but to remove the valve from the car. It is worth noting here that if in your car, in order to get to the exhaust valve, you have to dismantle many components in the engine compartment, then there is no point in cleaning it, etc. work. In this case, it would be more advisable to simply install a new valve, since when cleaning it in the future, you may need to remove it from the machine again, which will again be associated with huge financial costs.
We also draw your attention to the fact that when replacing the EGR valve with a new one in many cars, you may need to re-register the new valve in the engine control unit using a computer. That is, in essence, you will need to teach this new valve to work exactly as it was intended by the automaker.
As you already understand, friends, to set up the operation of a new valve, you need special diagnostic equipment (a computer automotive scanner). If you do not have such a device, then after replacing the exhaust valve you will have to contact a technical auto center.
