Top 10 EGR Valve Failure Symptoms in a Vehicle.

EGR valve failure symptoms can be found in a vehicle. The EGR valve helps to control and regulate the exhaust gases coming out from the engine and also uses this gas to create a rich mixture in the engine. In this article, I will discuss the details of the top 10 EGR valve failure symptoms in a vehicle.


What is an EGR Valve?

The Exhaust Gas Recirculation(EGR) valve is found in an Internal Combustion Engine. In exhaust gas, there is also an amount of nitrogen oxide, which makes the environment polluted. This NOx needs to be eliminated from the air, to make the environment clean.

The primary function of an EGR valve is to eliminate the Nox gas from the exhaust by passing it to the engine combustion chamber. This NOx is a very hot gas that can directly increase the volumetric efficiency of the engine and produce a rich mixture for the engine.

The EGR valve is controlled by the engine control module (ECM) or engine control unit (ECU), which regulates the amount of exhaust gas recirculated based on various factors such as engine speed, load, and temperature. While EGR systems play a vital role in emission control, issues with the EGR valve or related components can lead to performance problems, increased fuel consumption, and increased emissions. Regular maintenance and periodic cleaning of the EGR valve are recommended to ensure optimal functionality.

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EGR Valve Failure Symptoms

EGR valve is an important component in an Internal Combustion Engine. This EGR valve helps to recirculate the exhaust gases and pollutants parts in the engine combustion chamber. The top 10 EGR valve failure symptoms are discussed below-

  1. Check Engine Light
  2. Rough Idling
  3. Poor Acceleration
  4. Increased Emission
  5. Reduced Fuel Efficiency
  6. Engine Stalling
  7. Knocking Sound
  8. Excessive Exhaust Smoke
  9. EGR Valve Stuck
  10. Carbon Buildup

#1. Check Engine Light

Engine light has the biggest sign of problem flashing on the car’s dashboard. This engine light indicates the failure sign of the engine parts. As the EGR is the functional component of the engine, then this failure signal would be displayed on the dashboard.

As this sign pops up, you need to check the engine if there are any leaks or not. Then bring the vehicle to your nearest vehicle care center and check the engine.

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#2. Rough Idling

Rough Idling is one of the problems among the EGR valve failure symptoms. In engine idle condition the throttle valve remains open partially and some of the exhaust gases enter into the intake manifold. Rough idling may lead to incomplete combustion cycles, causing a misfire or irregular firing of the engine. Incomplete combustion can result in unburned fuel and contaminants in the exhaust gases, affecting the composition of the gases recirculated by the EGR system.

Continuous rough idling can cause engine damage and wear and tear on the parts. In modern cars, companies use sensors to detect the EGR valve opening and closing according to the engine requirements. So, checking regularities may help to increase the life of the engine.

#3 Poor Acceleration

Poor acceleration or the engine and low power decreases the outlet gas quantity. If acceleration is poor, the EGR valve may not receive sufficient exhaust gas flow, affecting its ability to operate optimally. Inconsistent combustion can also contribute to the formation of carbon deposits on the EGR valve and associated components.

If poor acceleration is happening inside the cylinder then the engine will face some serious issues like engine damage, valve problems, decreased fuel economy, etc.

#4. Increased Emission

Incomplete combustion is the main key to the increase in emissions. It deposits carbon on the engine piston and also creates uneven pressure on the crankshaft. These deposits can accumulate on the EGR valve, intake manifold, and other components, affecting the valve’s movement and functionality.

An EGR valve needs to be cleaned to rectify the path of the exhaust gases to the engine cylinder. This also leads to engine damage and EGR problems.

#5. Reduced Fuel Efficiency

The EGR system helps to control the fuel efficiency of a vehicle. Incomplete combustion, carbon deposits, or other factors like engine knocking, sensor malfunction, etc, are the problems in reducing the fuel economy. EGR valves help to increase the volumetric efficiency by adding an extra amount of rich mixture. So, there are less fuel is used in the higher RPM.

If the EGR valve is clogged or some malfunctions are found three then the system will fall and will create a problem. So, changing the EGR is the best option at that time.

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#6. Engine Stalling

EGR valve helps to suck out the emission gas forcefully and allows the fresh charge to do its job. If the engine acts like a knock or has too much noise then the EGR should have a problem. The exhaust gases do not clear out of the combustion chamber and then the engine stalls.

So, reduce this engine stalling the engine should be clear all the time, and use the perfect engine oil grade. The engine and the other parts like the fuel injection nozzle, fuel filter, air filter, etc., need to be cleaned on time.

#7. Knocking Sound

Incomplete combustion the engine stalling or improper engine timing causes the engine to knock. The improper operation of the EGR valve can cause irregular combustion, resulting in engine knocking or pinging. Engine knocking puts stress on the engine and can reduce fuel efficiency over time.

So, changing the EGR valve can help to reduce the engine emission also fuel efficiency. Engine knocking is the main and irregular problem for everyone, and causes the engine to have wear and tear.

#8. Excessive Exhaust Smoke

EGR valve helps to control the engine exhaust present NOx. This is a harmful gas and has a bad smell. If there is incomplete combustion or the engine is not performing well, then the EGR should not operate properly. So, the rectification of the gas is not done by the engine and causes problems with the engine cylinder.

So, check the engine before you start the engine, and also check the exhaust gases from the exhaust pipe. This is very important before going for a long ride.

#9. EGR Valve Stuck

The EGR valve is the main component of the circulation of the exhaust gas. If the EGR valve gets stuck in the body then the exhaust gases will continuously harm the atmosphere. The EGR valve helps to regulate the exhaust gas pressure and helps reduce the engine pressure.

If the EGR valve gets stuck there the engine stalling will happen. The Scavenging process will not be done properly in the engine. So, there is a high probability of engine damage.

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#10. Carbon Buildup

EGR valve failure can contribute to the accumulation of carbon deposits within the engine and on critical components, including the intake manifold and valves. Carbon buildup hampers efficient airflow and can lead to decreased fuel efficiency.

If carbon is deposited on the engine piston or in the EGR valve then the system will not function well, creating damage to the components.


Addressing EGR valve issues promptly through regular maintenance, cleaning, and, if necessary, replacement can help maintain fuel efficiency and overall engine performance. Regular vehicle inspections and adherence to recommended service intervals are essential for optimizing fuel efficiency and preventing EGR-related problems.

Frequently Asked Questions(FAQ’S)

How does the EGR valve work?

The EGR valve regulates the flow of exhaust gases into the intake manifold. It opens and closes based on signals from the engine control unit (ECU), adjusting the amount of recirculated exhaust gas depending on driving conditions to optimize emissions and engine performance.

Can I clean the EGR valve myself?

Cleaning the EGR valve can be done as a DIY task for those comfortable working on their vehicles. However, it’s essential to follow manufacturer guidelines and use appropriate cleaning agents. If uncertain, consulting a professional mechanic is advisable.

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