The engine mostly uses a mixture of air and fuel to burn and propel the piston. The environment air has only 20% O2, 80% nitrogen, and other trace elements. As air ignites in the combustion chamber in combination with fuel, the temperature rises to over 1,300°C. If air is burned at such a high temperature, even noble gases such as nitrogen can burn to form oxides. These gases produce air pollution and are harmful to human health. The function of the EGR valve is to return the exhaust gases to the burner, lower their temperature and prevent the formation of nitrogen oxides.
These valves are most commonly used in petrol engines. It is a part of the petrol engine that facilitates the entry and exit of gas into the combustion chamber by simply opening and closing the valve.
The EGR effect does not change regardless of the engine system configuration. Like everything in nature, these EGR valves are limited and prone to failure. Since it’s expensive to replace every time, we’ve listed some common signs of EGR valve failure. This is because it is cheaper to clean and preferable to replacing, so you can check it out carefully.
Signs of a failing EGR valve
Following are the most common signs of bad EGR valves:
1) Poor Mileage
For the average Indian, this is possibly the most appalling horror. Because, besides the World Cricket Championship, that is something that India as a whole wants. If the EGR valve is opened, the temperature in the combustion chamber drops, and fuel consumption is significantly reduced. This reduces the ignition efficiency of the internal fuel and shortens the long-term engine life.
2) Loss in Performance
If the EGR does not move to the open or closed position, acceleration performance may degrade. The main reason for this is an incorrect fuel-air mixture in the combustion chamber. If the valve does not move when it is open, too much exhaust gas enters; if it is kept closed, the exhaust gas increases.
3) High Emission Rate
If the vehicle fails the emissions test because the number of points is higher than the permitted value, it may be due to a malfunction of the EGR valve. I’m not saying the EGR valve is the only reason, but it’s best to ask an expert for confirmation. If it clogs with the EGR valve closed, the exhaust gas is not recirculated, the exhaust gas gets out of control, and the exhaust gas rises.
4) Knocking Sound
If the EGR valve remains in the closed position, the temperature in the combustion chamber continues to rise and exceeds the threshold. This can cause the fuel to ignite and knock faster than expected, especially if the engine is slow. Once you understand the concept of detonation, you will find that long detonations are very bad for the engine.
5) Rough Engine Idling
If the EGR valve remains in the open position, the recirculation cannot be controlled and the exhaust gases entering the combustion chamber can be too low or too high. This also leads to an incorrect internal air/fuel mixture (ideally perfect), which makes the engine unstable when idling. This is also indicated by a rattle.
6) Smell of Fuel
Nitrogen oxides released from car tailpipes are not only harmful but also have a very pungent odor. Also, when the EGR valve is not working properly, the engine can burn more fuel and release more hydrocarbons. They mix with the added NOx to create a dangerous and noxious mixture of gases.
7) Engine stalls while idling
If the EGR valve remains in the open position, not only will the idle speed get rough, but the engine may also stop while idling. Well, this may seem less dangerous than stalling a moving car, but it certainly means that the EGR valve is clogged or has malfunctioned so it won’t go any further. Must be careful.