What does the EGR valve do? How does the EGR-valve work? What are the symptoms of an EGR valve malfunction? How do you replace an EGR Valve? What should you do if your EGR valve breaks ?….
What is the function of the EGR Valve
The EGR valve is an essential component of countries that have emission regulations and plays an important role in controlling exhaust emissions.
For combustion to take place in an engine, it is necessary for air to contain approximately 80% nitrogen (20% oxygen). Air reacts with fuel to produce combustion. Meanwhile, the combustion chamber temperature rises to an average of 1370°C (2500°F).
These high temperatures cause the formation of nitrogen oxides (NOx). The most harmful pollutants in automobiles is NOx. It can cause respiratory problems and adversely affect human health.
Exhaust gases must be cooled to reduce NOx pollution. An Exhaust Gas Recirculation valve (EGR), is required to achieve this. These polluting gases are returned to combustion chamber at a rate of between 5% and 15% by the EGR valve. This reduces the temperature of the combustion chamber and prevents the production of NOx emissions. This also increases fuel efficiency.
How does the EGR valve work?
An electropneumatic device that opens and closes, the EGR Valve is an electronic valve. It opens to allow exhaust gases to enter the combustion chamber. When the engine starts, the valve should be kept closed. The valve will open gradually as the engine heats up or the vehicle accelerates. The valve closes slowly if the vehicle slows or comes to an abrupt halt.
This occurs continuously throughout the recirculation cycle. This ensures that the vehicle emits less carbon dioxide and fuel efficiency.
EGR valves are used in modern gasoline and diesel vehicles. There are two types: electronically controlled and vacuum-operated EGR valves. Older vehicles often have vacuum operated valves. This simple vacuum assembly opens and closes the EGR valve. The solenoid is controlled by a computer.
The EGR valve is an electronic control device that most modern cars use. It is controlled electronically via the ECU (engine computer). The ECU is able to receive data from many sensors and adjust the EGR Valve position during your journey.
EGR Valve Malfunction Symptoms
EGR valve problems can include reduced engine power, misfires and fuel consumption. It can also increase vehicle emissions.
EGR valves may become “open” and “closed” by a buildup of soot particles or carbon deposits as well as fuel contamination. Your EGR valve is most at ease in highway driving conditions. Long trips enable the engine to heat up enough to eliminate carbon deposits. These deposits increase in urban driving conditions.
Modern cars can be equipped with an ECU (Engine Control Unit) that detects problems with the EGR and displays a warning on their dashboard.
EGR valve failure is characterized by the appearance of these symptoms:
- – Turn on the engine light
- – Idle imbalance
- – The engine starts to hum and knocks
- – Sudden acceleration and misfires
- – Loss in performance
- – An increase in fuel consumption
- – A rise in emission values
- – Strong odour of sulfur or fuel
Below are the most frequent fault codes that can be associated with an EGR valve failure.
- – P0401: Insufficient EGR Flow
- – P0402- Excessive EGR flow
- – P0403 – EGR Circuit Malfunction
- – P0404 Exhaust Gas Recirculation A Control circuit Range/Performance
- – P0405 EGR Sensor A Circuit Low Input
- – P1404 EGR Valve Stuck Position Open
- – P1406 – EGR Valve Position Sensor Circuit Problem
Notice: The fault codes can vary depending on the vehicle’s make and model.
What Happens if The EGR Valve Breaks?
1- Exhaust Particles (Partly-Burned Fuel): Increase in
EGR valves that are clogged or faulty can increase exhaust particles, causing diesel particulate filters to clog faster.
2- Increased Problems with Blasting and Fuel Consumption
In the combustion chamber of an engine, small explosions can occur. This can lead to engine overheating, mechanical damage, and abrasions. The constant openness of the valve can increase fuel consumption. Because the temperature in the combustion chamber will decrease, fuel efficiency will suffer.
3- Misfires and Idle Irregularity
The EGR valve must be closed properly to prevent exhaust gases from leaking into the intake manifold. This could cause misfires or irregular idling. Your vehicle could also stall when it is idle.
4- Difficulty in Starting the Vehicle and Performance Problems
If the EGR valve is left open, vacuum leaks can occur to the intake manifold. This could cause the vehicle not to start. EGR valves that are permanently or temporarily closed can cause poor performance.
5- Sharp Fuel Smell
You may notice a fuel smell if there is constant gas flow in the intake manifold. Because fuel is not burned at low temperatures, it can cause unpleasant smells. The amount of hydrocarbon gas emitted from exhaust pipes increases dramatically.
Removal or cancellation of the EGR Valve
It is not recommended to remove or cancel EGR valves. It is common to believe that removing or cancelling EGR valves will make the car more efficient. This is false. You will have to pay more for fuel if your vehicle fails emission tests.
How do I replace the EGR valve?
1) Place the vehicle in park and engage the handbrake. The owner’s or repair manual will provide information on how to locate the EGR Valve.
2- Turn off the engine and unplug the battery.
3- Inspect all vacuum lines. Look out for holes, tears, and rips. As needed, make adjustments.
4- Disconnect the vacuum line from EGR valve.
5- Unscrew the bolts holding the EGR valve to cylinder head.
6- Disconnect the EGR valve. You must protect the open cylinder head against dirt.
7. Install the vacuum line and bolt the EGR valve.
8- Connect your battery.
9- Start your vehicle, use the diagnostic instrument to check for fault codes and reset check engine lights.
10- Test the engine by taking it for a drive.
