What is an exhaust gas recirculation system ? Not every car owner can answer this question, however, absolutely all types of modern engines are equipped with this system - from gasoline and diesel to gas. This system plays a very important role in the functioning of the car, so you should definitely understand what it is. And this article will help you with this.
Here you will find out what the exhaust gas recirculation system is, how it functions, what benefits the car brings, as well as how breakdowns of this system can be fraught with and how to avoid them. This information will help you better know your car, as well as prevent some unpleasant situations associated with the system, which will now be described in this material.
What it is?
So what is an exhaust gas recirculation system? It is often called EGR - this abbreviation comes from the English name of the system, but it is very often used by all Russian-speaking car enthusiasts, since it is much more convenient. So what is this mechanism? The exhaust gas recirculation system is responsible for reducing the level of nitrogen oxides in the exhaust gases . This is achieved by returning some of the gases back to the intake manifold. Naturally, at first glance, all this may seem like rather strange and incomprehensible words, however, as you read through the article, you will begin to understand more and more exactly what this system does, and why the car needs it.
How it works?
The EGR exhaust gas recirculation system operates in a fairly simple manner. The fact is that when fuel is burned in the combustion chambers, nitric oxide is formed, which is incredibly toxic. And if it gets into the air along with exhausts, then the cars will poison the environment very much. The higher the temperature in the combustion chamber, the more nitric oxide is released, so something needs to be done with this process. Exactly here the EGR exhaust gas recirculation system comes into play - with its help a part of nitric oxide is fed back to the intake manifold.
The valve is responsible for the supply of exhaust gases, which opens only when the supply is necessary, and closes when the gases have already arrived in sufficient quantity in the intake manifold. From there, the gases, together with the fuel mixture, enter the combustion chamber, where the mixture is accordingly burned, and the supplied gases lower the temperature of its combustion.
As you can see, the system is extremely simple, it functions reliably and continuously, so you can not worry about problems that would arise if it were not there. The process of operation of this system is understandable and the purpose of its existence, in general, is also. But it is still worth taking a closer look at exactly what advantages it gives in order to finally realize how important it is for the car.
What does it give?
What really does an EGR exhaust gas recirculation system do? First of all, we are talking about reducing exhaust toxicity. As mentioned earlier, nitric oxide is extremely toxic, so its high content in the exhaust would make cars impossible to use. And with the help of this system, these toxic gases are used inside the car and do not enter the environment. But this is not the only reason why this system functions.
It is also worth paying attention to the fact that incoming re-exhaust gases occupy part of the volume of the combustion chamber, thereby reducing the amount of fuel burned. As a result, this gives small savings on gasoline, diesel or other fuel that you use to move on your vehicle. Naturally, the savings are not very large, but still any little things are welcomed in this matter. And do not forget that through the use of nitrogen oxides, the EGR exhaust gas recirculation system reduces the oxygen content in the fuel mixture, which allows you to effectively deal with the extremely unpleasant detonation phenomenon, which happened quite often before the introduction of this system.
Initial option
This system first appeared on automobiles in 1972, however, the first experience with its use turned out to be completely failure. The fact is that then the valve was always in the open state, that is, the exhaust gases flowed into the intake manifold in any engine operation mode. It would seem that this is bad? But there was a lot of bad things, since the gases cooled the combustion chamber even when this was not necessary, for example, when the engine was warming up.
Due to the decrease in temperature in the combustion chamber, the engine warmed up much more slowly, which caused dissatisfaction with motorists. Moreover, there was absolutely no control of the gas supply - even when you need to squeeze the maximum out of the car, that is, to achieve the maximum allowable temperature in the combustion chamber, gas was supplied there, which reduced the car's power. That is why the first model of the system was a failure and did not receive further development.
disadvantages
Fortunately, another independent Ford exhaust gas recirculation system was introduced that year, which was much more advanced. It had an automated valve opening and closing system for specific engine operating conditions. At a low temperature in the combustion chamber, the valve closed, allowing the motorist to calmly warm up the engine. The higher the temperature in the combustion chamber rose, the wider the valve opened, letting more and more gas flow for cooling. However, the lack of feed control remained, which led to the fact that the use of this system was associated with a number of some disadvantages.
Chief among them was the fact of power loss due to the fact that the temperature in the combustion chamber always remained optimal and did not allow voluntarily to achieve full power from the engine. However, at that time, the system was the ultimate dream and for many years it was it (of course, with some improvements and updates) that was used on all cars. Moreover, you can still find cars on which a similar exhaust gas recirculation system is installed - Niva is one of the most striking examples.
Modern model
However, is there really still only the same exhaust gas recirculation system? Niva and other Russian cars of the old model really use it, however, in fact, the mechanical version has long been outdated and remains on the machines only as a relic of the past. In the modern world, electronic systems are used that provide complete control over the operation of the valve. Now the machine has a sensor for the exhaust gas recirculation system, which monitors both the temperature in the combustion chamber and many other parameters on which the functioning of this system depends.
Accordingly, in the modern version of the system, the problem that engine power is reduced when using EGR is completely eliminated. Some of the models of current systems do not use a separate valve for gas redistribution at all, since the “brain” of a car controls the gas distribution phases, due to which, accordingly, the recirculation process is also controlled. Thanks to this approach, the engines were simplified, saving them from unnecessary parts. However, this system is the most modern, therefore it is used far from everywhere and has a high cost. But perhaps in the future it will spread and become more accessible to everyone. And perhaps it will be replaced by another, more advanced system. But this is all speculation - now you need to focus on what is happening here and now. And even better - on what is happening in the context of Russian reality.
What is the risk of an exhaust gas recirculation system installed on a VAZ? 21213 is a VAZ-a model that can be equipped with EGR. But is this system really effective in Russia, and not in America or Europe?
EGR in Russian conditions
In theory, this system is an excellent addition to the car - it only benefits and does not portend any harm at all. And in European conditions, where the fuel is of the highest quality, and people are willing to pay for everything to work well, this is true - EGR shows perfect results and one hundred percent satisfaction among motorists. But what in Russia? Is it really that different?
It turns out more than enough. The fact is that the quality of fuel that is distributed on the territory of the Russian Federation is much lower than in Western countries, so the recirculation system becomes clogged much faster. As a result, this leads to the fact that the valve of the exhaust gas recirculation system fails much faster. This can be corrected at a service station, but the cost of replacing the components of this system is quite high, so many Russian residents refuse to spend extra money on such a system. As a result, they simply jam it, that is, fix it in one position, preventing its further functioning.
Accordingly, EGR in modern Russian conditions is an actual system only for those who can afford the purchase of high-quality fuel and planned expensive repair of the system. The average Russian citizen either can’t afford it or doesn’t want to do this, therefore more and more people prefer to shut off the valve of the exhaust gas recirculation system, saving themselves from unnecessary problems. And here a very interesting question appears. Do they really get rid of problems? Or just add even more trouble?
Should I turn off the recirculation system?
You already know how the exhaust gas recirculation system works in a car, and you can also imagine what benefits it can bring to a car. However, there is no agreement among motorists on this issue - people are divided into two opposite camps, each of which is confident in its correctness. The first camp includes those who are of the opinion that the recirculation system really works, it can reduce exhaust emissions, increase engine efficiency and reduce fuel costs.
However, there are opponents of this idea, which make up the second camp. They prefer to jam the EGR at the earliest opportunity - this is done quite simply. It is necessary to cut a gasket from thin sheet, which is placed under the valve of the system, fixing it in one position. As a result, it cannot move, and the system stops its work.
Many people say that the recirculation system only harms cars, so jamming it will only give positive results. Some propose to conduct an experiment - to swipe the inside of the exhaust pipe in a car where the EGR system does not work. You will have a black coating on your finger, the main part of which will be soot. It is she who, according to such experts, along with other contaminants is fed into the combustion chamber, quickly polluting it and causing engine damage.
There are those people who belong to the second camp, but do not adhere to such radical views. They also believe that the system can be quietly drowned out, but only for the reason that it does not bring particular benefit to the car, but at the same time it requires cleaning and repair during operation. Therefore, they prefer to jam the system so as not to give out extra money for this very repair.
Breakage
If we are talking about malfunctions of the exhaust gas recirculation system, then it is worth looking at them more closely. What can they be and what consequences can they ultimately lead to? There are a large number of different options for minor malfunctions, an impressive part of which is connected precisely with the fact that the recirculation system is very clogged. This occurs during the use of the car, so it is simply impossible to avoid such an effect.
If you study the documentation for this system, you will be able to find out that on average it is designed for full operation over 70-100 kilometers. After that, you should definitely contact specialists to carry out a planned replacement of spare parts. And, as you already learned earlier, this replacement costs a lot of money, so many people try to avoid it in all ways. Especially in Russia, because of the poor quality of fuel in the country, the life of such a system is reduced to about fifty thousand kilometers. As a result, if you do not carry out a scheduled repair, then you may experience certain breakdowns and malfunctions.
One of the most common problems is valve leakage due to prolonged use. As a result, it happens that gases begin to flow in abnormal quantities, additional air also enters the intake manifold, which negatively affects how the exhaust gas recirculation system functions. Failures as a result lead to not the most pleasant consequences.
- Firstly, due to uncontrolled intake of gases and the presence of excess oxygen in the fuel mixture, it is depleted. What does it mean? That instead of reducing fuel costs, they increase, since the fuel mixture is less efficient, and the engine has to let in even more fuel.
- Secondly, this can lead to the opposite effect - to excessive enrichment of the fuel mixture, since the pressure in the intake manifold will increase significantly.
Depending on the type of system, you can observe either one effect or the other - there is also the possibility that they will appear alternately. For example, at idle, the mixture will be overly enriched, and when switching between modes, it will become sharply depleted. It’s not even worth telling how harmful it is for the engine and what fuel overruns it leads to. What to do in case of a malfunction?
Recirculation system repair
If your car already has problems with the exhaust gas recirculation system, then you should definitely contact the specialists who will conduct you a comprehensive repair and replacement of the necessary parts. As already mentioned above, in European and American conditions, that is, in the presence of high-quality fuel, such a service will be enough to carry out once every hundred thousand kilometers. In Russian conditions, this must be done twice as often, that is, every fifty thousand kilometers.
But what if you do not want to pay for repairs? There are two ways out, and both can only be used when your system is completely repaired or new. So, the first option is constant timely preventive care for the recirculation system. This involves cleaning the key elements of the EGR, that is, directly to the valve itself, as well as the solenoid. The valve must be cleaned so that there are no traces left on it that would interfere with its tight closure.
As for the solenoid, it has a tiny filter that you need to pay attention to. It is you who need to clean it so that it continues to protect the vacuum system from the ingress of various types of contamination.
The second option, which was already mentioned earlier, is the jamming of the recirculation system.