Exhaust Gas Recirculation (EGR) is a technique to reduce emissions, used in internal combustion engines, by recirculating a part of the engine's exhaust gas back into the intake manifold.

The EGR valve has a direct impact on the car's gas emissions, which means that any kind of failure can raise the level of pollution caused by the vehicle and, implicitly, can lead to substantial fines. 

What you need to know about the EGR valve?

The EGR valve is part of all modern engines and became increasingly demanded after it was proved that vehicles cause most of the air pollution, and the fact that the automotive industry is a significant part of everyday life. It has made specialists in the field to do their utmost to develop technologies that reduce pollution globally.

Knowing an EGR valve and the role it plays helps drivers to bring their car's pollution level to a minimum to avoid financial penalties, but also to show concern for the environment.

It is also important to know that the EGR valve on a car must be included whether it runs on a diesel or petrol engine and in both cases plays the same role. However, due to the pollution power of the basic fuel, namely diesel, the EGR valve can be considered more important in the case of diesel engines.

How did the EGR valve appear?

EGR officially appeared in 1970, when it could be included as a part in a car engine and was considered an acceptable measure to reduce carbon emissions, especially those caused by diesel cars. However, the intention to develop such a car part appeared as early as 1940 and, for 30 years, multiple experiments were made for this purpose.

In the USA, the EGR valve was included in all petrol-powered cars between 1972 and 1980, and in 1990 this valve began to be removed from gasoline cars, opting for its inclusion in the diesel engine, especially in the case of family cars or trucks. The popularity of the EGR has grown since the early 2000s and over about a decade it has been proven that an EGR valve helps both to limit carbon emissions and reduce fuel consumption.

What is the role of the EGR valve?

The role of the EGR valve can be determined from its name, which is an acronym for Exhaust Gas Recirculation. Thus, it can be said that its main purpose is to restore the gases emitted in the combustion cycle. However, the process is much broader and does not involve capturing the entire amount of gas, but only a part to be reintroduced into a combustion cycle.

The reason for this process is to reduce the level of emissions caused by cars that are harmful to the environment, especially due to the fact that vehicles are currently responsible for much of the pollution that affects the planet at global level.

In addition, the EGR valve can help keep the engine running smoothly, preventing it from drowning or increasing fuel consumption. The role of the valve has become a priority for most vehicle manufacturers, aware that the automotive industry has an extremely high impact on the environment both in the way vehicles operate and in the way they are produced.

How does the EGR valve work?

The EGR valve does not operate constantly, but only when the machine is idling or when the engine is performing low or medium loads and shuts off at high loads to allow the engine to run at full capacity.

The gas recirculation process begins when the EGR valve receives commands from the ECU (Electronic Control Unit) or “Electronic Control Unit” to capture some of the emitted gases and reintroduce them into the intake for a new combustion cycle, in time. that the shutter can reduce the pressure in the intake manifold because it controls the flow of flue gases inside supercharged engines.

After re-entering the combustion cycle, the captured gazelles are cooled to a temperature of approximately 160 ° C from an estimated value of 750 ° C by means of the coolant.

The EGR valve can also be programmed to operate under specific conditions, and maximum capacity can be reached when the engine load is low or medium while the emissions exceed the permissible limit.

EGR valve maintenance

Like any car component, the EGR valve needs proper maintenance to operate at full capacity and to reduce toxic gas emissions as much as possible.

In addition, the maintenance of the EGR can directly influence the operation of the engine, as the retention of flue gases can lead to its drowning, while the total elimination of gases without being put back in the combustion cycle has a negative impact on the environment. The second scenario increases the pollution power of the vehicle, which is a potential financial penalty.

The complexity of the maintenance process also depends on the type of EGR valve. In the case of valves with a simple recirculation system, maintenance is easy. On the other hand, where there is a recirculation system with intermediate cooling, the maintenance is more complex, but also the system is more efficient, because it includes central pipes for the circulation of exhaust gases, the coolant flowing past these tubes, taking heat from the gases. evacuation. In this way, the density of the flue gases introduced into the engine increases.

Symptoms of EGR valve failures

The EGR valve can break down for many reasons. Such problems can lead to faulty combustion inside the engine causing excess gas to lead to carbon deposits. However, before an irreparable failure, the engine will show some symptoms that show that the EGR valve is not working properly.

There are some basic symptoms that apply to both diesel and gasoline engines. These involve malfunction when the car is idling, lack of vehicle power, slow acceleration or increased fuel consumption.

However, in the case of diesel engines, other symptoms may occur, such as an excess of soot in the smoke emitted by the car, which is not easily observable with the naked eye. Therefore, drivers who drive diesel engines are advised to do regular particulate filter checks, preferably at a specialist car service center.

Cleaning the EGR valve

The only solution to restore the operating capabilities of the EGR valve and to ensure its longer life is cleaning. This must be done regularly, but also when the car has specific symptoms. Extra attention must be paid to this process when the car is used a lot in the urban environment.

If carbon deposits are observed in the EGR valve, it means that defective combustion has taken place. Thus, these deposits must be cleaned with a cleaning spray specially designed for this purpose. A spray can be replaced in case of force majeure with a good quality solvent, but secondary variants should not be used regularly. It is also advisable to call a car service and apply the necessary solution in case of problems with the EGR valve. This process is quite cheap and fast, regardless of the type of service used.

EGR valve maintenance measures

The main maintenance measures for the EGR valve include regular check-ups and increased attention to any of the symptoms that may occur if burns do not occur properly.

For diesel engines, the particulate filter can also be used as a method of monitoring the EGR valve.

In addition, it is good to know that the symptoms of malfunctions are more and more obvious as the outside temperatures drop. Also, using the engine at full capacity does not require the operation of the EGR valve, which means that a car used predominantly outside urban areas is less prone to malfunctions than one that runs frequently in the city.