What is the EGR and what role does EGR ❤Iron Vrom plays

What is EGR?

The EGR recirculation (exhaust gas), also called EGR valve, EGR or Flap EGR valve, is a system that has the role of recirculating exhaust gases, being part of the drain circuit. It is positioned in the engine compartment, between the suction section and the exhaust system. Depending on how it is controlled by the engine injection control unit, it can be:

• Vacuumatic (usually at € 4), composed of: EGR valve control electrovalva, empty capsule, sometimes position sensor, EGR cooling device, vacuum tube.
• Electric (at € 5), consisting of an electrical control engine -Sep of the EGR valve, position sensor, EGR cooling device.

What role does EGR play and what does this do?

In short, the circuit works as follows: the air in hiring reaches the cylinders, where the combustion of hot gases occurs. The part is eliminated through the exhaust tunnel and another part reaches the EGR, then passes through a cooling device and returns to hiring.

The role of the EGR valve is mainly reducing nitrogen oxides, which are formed at temperatures above 1600 Kelvin (about 1300 orC), lowering the maximum temperature in the combustion chamber.

The EGR valve has two main positions: open and closed, although it can be found in any intermediate state. It is closed when the engine starts. During the void and low speeds, there is sufficient power, therefore a small amount of oxygen, so that the valve gradually opens. In the ranking, 90%can be opened.

The EGR flap is not permanently open, but only to ranks, at low and medium speeds or low temperatures (winter).

At high speed, when more couples and power are needed, such as complete acceleration, the EGR valve is closed, to allow more oxygen in the cylinder, obtaining a maximum start.

Rooming the combustion gases in recirculation, the temperature in the cylinders decreases considerably, since the fresh and cold air contains oxygen and hydrogen that produce explosion and burning at very high temperatures, unlike the recirculation gases that contain nothing, are strongly cooled before reintroduction to the aspiration, up to an optimal temperature of the engine and do not create the engine.

In both types of engines, the EGR valve uses to check when and in which quantities the exhaust gases will be added to the suction air. This component consists of a hub valve and a blade, which allows you to pass the passage gases or blocks the road for the engine intake system.

There are also some sensors, such as the meal meal of the MAF air, the engine control unit, which calculates the optimal quantity and emits the controls corresponding to the EGR valve. The EGR valve is controlled by a vacuum unit.

Upon opening the exhaust valve (inside), the way of the circulation of exhaust gases through the suction section is allowed. At one end of the EGR valve are the electronic connections that control the valve.

The other end consists of a connector that connects the valve to the cylinders. In the middle the valve has another part of the connection. The housing is also called the valve room. The real valve is hidden inside the valve room.

Types of EGR valves

The first systems used an emptiness valve, while the latest vehicles are electronically controlled. The main types are:

– EGR valves for high pressure diesel systems: detect the exhaust gases with a high flow and a high content of soot, before entering the Diesel particles filter. The soot is combined with oil vapors and can form sludge. The exhaust gases are then redirected to the suction tunnel through a tube or by some internal holes in the header with a secondary valve that creates empty in the suction tunnel.

– EGR valves for low pressure diesel systems: it depends on the exhaust gases after they have passed through the diesel particles filter. They have a lower capacity, but do not contain soot. The exhaust gases are then brought back to the suction gallery.

– EGR valves for petrol engines redirect the exhaust gases similar to those for high pressure diesel systems. The negative pressure generated in the cylinder sucks the exhaust gases and the flow is regulated by opening and closing the EGR valve.

– The EGR valves operated with negative pressure use a negative pressure electrovalva, through which the EGR valve is open and closed.

– Some valves are equipped with a feedback sensor that informs the engine control over the valve position. The digital EGR valves have an Electrovalva or Step -By -Step engine and, in most cases, a feedback sensor. They receive signals to adjust the size of the impulses from the engine control, to adjust the flow of exhaust gas.

Diesel engines of exhaust gas recirculation

In diesel engines there is a conflict regarding the recycling of exhaust gases. On the one hand, reduced emissions are the main objective, on the other hand emissions should be reduced as much as possible. While a high rate of exhaust gas recycling minimizes the formation of nitrogen oxides, during the combustion process the amount of particles (sooty) increases. Since in both cases there are maximum limit values, it is important to take into account the amount of ricce exhaust gases. Diesel engines produce soot especially when pregnancy increases. In order to avoid great solar emissions, when the car accelerates, the reaction valve should be activated as quickly as possible. The mechanical movement is performed electric or electric, with a servomotor (depending on the model).

Recirculation of exhaust gases to petrol engines

Here things are a little different, the goal is different. Instead of following the minimization of pollution emissions, the emphasis is on the reduction of fuel consumption. This is negatively influenced, especially in the operation with partial load, for gas exchange losses. These losses can be substantially reduced by adding exhaust gases. Direct injection vehicles are an exception. In their case, the losses are much smaller, because there is an excess of air even during operation with partial load. In conclusion, the recirculation of the exhaust gases in these models, as well as on diesel, is used to reduce pollutants.

How difficult is it to cancel the EGR?

People are inventive when it comes to changes of any kind, but it must be known that this process is illegal. There are «carpaci craftsmen» or «good boys» which will mount a dish inside the EGR that will block access to the gas and brings an update to the software with which the existence of the EGR valve is canceled. According to their theory, the consumption will be lower or increased by no more than 1 liter/100 km, the car will work correctly, the engine will work at low temperatures and the engine compartment will be «pharmacy». Apparently in their conscience, only the struggle is given: pollution against clean engine. The reality is much greater: the gases have not united in the passenger compartment of the car and poison passengers over time. In addition, it is not enough to cancel the EGR, because if you have DPF particles filter, it will also have to be canceled. This operation is the criminal act, it cannot be masked and its physical removal is performed by a «specialized» mechanic in this, which, in ignorance, does not know that during the cutting and elimination of all ceramic residues, the inhalation of millions of cancer particles.

Does your engine need EGR?

According to some specialists, the answer would not be no. It was mandatory introduced only to prevent world pollution, starting from 1970.

In direct injection petrol engines, the EGR valve presents the following advantages:

• Fuel consumption decreases
• Reduces the possibilities of the engine to provide failures
• The car no longer has to work with additive petrol

In addition to reducing Nox emissions, EGR valves can be used in small engines with the GDI system to reduce pumping losses, as well as to improve fuel combustion and reduce the probability of beating.

To diesel engines, its role is capital. The circulation of a motor vehicle on diesel without EGR cannot be conceived, pollution with nitrogen, monoxide and carbon dioxide is quite dangerous, both for the environment and for those of the machine, because the passenger compartment is invaded by toxic gases, without being observed by those by car and long -term. In addition, it also helps to reduce the blows.

The cleaning of EGR costs between multiple dozens and 2-300, depending on the method of realization or the model of the car and must be made at about 50,000 km. Its replacement, if it is too late for cleaning, is between 250 and 500 she, depending on the model and is performed at 150,000 – 300,000 km.

Before asking for the problem to cancel the EGR, it is good to think about all the misfortunes produced by air pollution with exhaust gases, the future of your children/grandchildren and the fact that you will not pass the ITP inspection, in the happiest case, or you will choose with a criminal procedure or perhaps some of your family will contact your illness, in your car. Maybe not this year, but sometimes, soon. Ask your conscience.