What Is an EGR Valve | Cars and Motors
– EGR valve: what is it used for?
– Common EGR valve failures
– EGR valve: how to remedy failures?
– Price of an EGR valve
The EGR valve allows exhaust gas recirculation. It was adopted in Europe in 1996 on diesel passenger cars to meet the European EURO2 standard for air pollutant emissions.
Let’s zoom in on its usefulness and the most common breakdowns that we are likely to encounter.
EGR valve: what is it used for?
This valve is used to reduce nitrogen oxide (NOx) emissions generated by incomplete fuel combustion:
– The EGR valve opens to allow exhaust gases to flow into the intake duct, following certain engine cycles to burn them a second time and cool them down.
– With a lower gas temperature, the amount of NOx is significantly reduced.
Common EGR valve failures
Valve is stuck in the open position.
Fouling the movable valve with exhaust gas particles mixed with oil vapor residue forms a compact, sticky scale. This is often caused by short trips at low speeds with a cold engine. The valve may simply be defective.
A blockage of the EGR valve in the open position is characterized by:
– a loss of engine power;
– no revving up;
– jerking during acceleration;
– Smoke in the exhaust;
– The engine management light is on.
EGR valve blocked in the closed position
The same reasons are given as for the valve being blocked in the open position.
The engine management light is on to recognize that the EGR valve is blocked in the closed position. However, on some cars, you may not be able to see this.
Please note: the EGR valve blockage in the closed position does not affect the engine’s operation.
EGR Valve: How do I fix it?
You have two solutions if your EGR valve fails:
Add cleaning additives: car care manufacturers market cleaning additives to help clean the valve; however, there’s little chance of this working if it’s stuck tight.
– Disassemble the valve: A disassembly will be necessary to clean it and the intake pipe, and if that doesn’t work, a replacement with a new valve is necessary.
Please note: on some vehicles, the EGR valve is not very accessible and difficult to disassemble without good mechanical knowledge and tools. In this case, it is better to see a garage.
After repairing the EGR valve, a vehicle’s engine is warm after 20 minutes of driving in the city or 20 km on the road. At this point, you can carry out regular accelerations (3,200 to 3,800 rpm over 300 to 400 meters in third gear, for example).
This will limit engine fouling over time and remove oily particles from the EGR valve and the intake pipe.
Price of an EGR valve
The price of an EGR valve varies between $100 and $400, depending on the vehicle’s make.
The replacement time is about 1 to 4 hours, depending on the vehicle model and the difficulty to disassemble them. Indeed, they are often stuck or seized in their housing.
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