It was determined that in the exhaust gases created by the combustion of air and fuel in vehicle engines, harmful nitrogen oxides are created, so the engineers came up with the idea to install an EGR valve instead of installing filters for these harmful gases (SRC filters). which will return some of these harmful exhaust gases back to the chamber where the lower combustion temperature will now avoid the formation of hamful gases.
The logical question is that oxygen is not needed to burn fuel, but the answer is that the air itself has more nitrogen than oxygen, and that after burning fuel, oxygen actually binds to nitrogen from air and then there is less oxygen left for efficient engine operation, until the temperature of further combustion drops, and then there is more oxygen and the engine can of course work better and with more power ..
It is clear that according to the basic function it performs, the EGR valve opens and closes as needed cyclically, and that its function is one and always the same, which is to redirect and introduce exhaust gases into the combustion chamber or to accumulate and prevent them in it. their entry.
When the engine is started, the EGR valve is closed and it blocks the flow of exhaust gases, but when the engine increases speed and reaches the so-called operating temperature, the EGR valve gradually opens either electronically or through a vacuum, and then gases enter. exhaust gases are ignited in the combustion chamber, where they mix with fuel and air.
In general, it is a fact that most faults on the EGR valve occur due to its construction, because it is constantly exposed directly to exhaust particles that create soot deposits and therefore the EGR valve is stuck and remains either permanently open or permanently closed.
When it comes to the most significant symptoms of EGR valve failure, they can be roughly divided into two basic types, namely the symptoms that occur when the EGR valve is constantly open and the symptoms that occur when the EGR valve is constantly closed.
When the situation arises that the EGR valve is open, then there is a constant entry of exhaust gases into the connector and as a consequence there is one or more of the following signs and manifestations of failure - there is a loss of idle speed after starting the engine. when it is still cold; spot lights flicker sometimes at very low speeds when the engine is warmed up; the MIL illuminates on the control panel or the fault indicator light or the mentioned "check engine" light comes on.
As symptoms of EGR valve failure when it is open, there are also - increase in fuel consumption; loss of engine power so the car pulls worse; a milder or stronger smell of fuel is noticeable when the engine is running, because then the concentration of hydrocarbon gases coming out of the exhaust system increases.
On the other hand, when the EGR valve is closed, the main manifestations of the fault are caused by permanent blockage of the exhaust gas flow in the connector, and such symptoms - when the engine is at low speed (but at speeds greater than idling). ), m there is a banging and "whistling or whistling" coming from the engine; after a normal ignition, a second or secondary ignition may occur suddenly and they may combine and become so powerful that they may damage the engine; detonations that are quite loud appear; the vehicle cannot perform the exhaust emission function.
Namely, as there is a fault in the EGR valve and as it is closed in this case, it is not possible to emit exhaust gases. and then it starts again as in the previous case to light up the malfunction sensor MILili the "check engine" light comes on.
When deposits or dirt form on the EGR valve and this is manifested by one or more of the above symptoms, it is necessary to clean the EGR valve, and the interval of regular cleaning certainly depends on the degree of soiling and the degree of soot accumulation that creates a risk of failure and jamming of the valve, so it is recommended to clean the valve preventively in a shorter time
Pozdrav od Mrkija 🇷🇸 - Greetings from Mrky 🇺🇸
