Although we petrolheads hate to agree that automobiles are one of the main sources of pollution that are damaging the environment, it is, unfortunately, a fact. But we obviously cannot give up on our first love so easily, can we? That’s the reason we come up with things to reduce the harmful exhaust gases and one of them is the EGR valve. In this article, we explain what is an EGR and the common signs of a failing EGR Valve.

What is an EGR and how does it work?

EGR Valve diagram
EGR Valve diagram

An engine basically needs a mixture of fuel and air in order to burn and push the pistons. The outside air contains only 20% Oxygen and 80% Nitrogen, along with other minor elements. When this combines with fuel and ignites in the combustion chamber, temperatures rise above 1300°C. The combustion at such temperatures burns even inert gases like Nitrogen, resulting in its oxides. These resulting gases are air pollutants and have injurious effects on our health. The role of the EGR is to send the exhaust gases back into the combustion chamber thereby reducing its temperature and avoid the formation of nitrogenous oxides.

The EGR valve is a small component that is designed to facilitate the movement of gases in and out of the combustion chamber by simply opening and closing the valve. The role of the EGR stays the same irrespective of the engine system configuration. Like everything in nature, these EGR valves also have limitations and tend to fail. Replacing an EGR valve will cost you upwards of 18k and you can buy one from GoMechanic Spares here. And replacing it every single time is a costly affair, hence we list a few common signs of a failing EGR valve so that you can stay cautious and get it checked as cleaning it is more economical and advisable than replacing it.

Here are the 8 common signs of a failing EGR valve :

  1. Poor Mileage

    Bad fuel economy can mean an engine problem
    Poor Mileage

    This is hands down the worst fear for an average Indian as this is one other thing that entire India wants apart from more cricket world cups. When the EGR valve is stuck in its open position, there will be a considerable drop in fuel efficiency and this happens due to the temperature inside the combustion chambers being lower. This leads to inefficient ignition of the fuel inside, which in long term could cause harm to the life of the engine as well.

  2. Loss in Performance

    Hyundai i30 Fastback N
    Loss in Performance

    If the EGR is stuck in an open or closed position, then there might be a decrease in performance, say while accelerating. This happens mainly because of an incorrect mixture of air and fuel mixture inside the combustion chambers. If the valve is stuck while being open, then it allows too much exhaust gas in and if it’s continually closed, then your emissions will rise.

    Get your car serviced at GoMechanic

  3. Higher Emission

    Excessive smoke from the tailpipe
    Excessive smoke from the tailpipe

    When you experience your vehicle failing the emission tests due to a higher score than permitted then it might be due to a faulty EGR valve. We are not saying that the EGR valve is the only reason but it is better to get it checked by an expert. When the EGR valve is stuck while being closed then it will not be recirculating the exhaust gases and there will be no control over the exhaust gases which causes more emissions

  4. Knocking Sound

    Engine Knocking
    Engine Knocking

    When the EGR valve is stuck in a closed position, the temperature inside the combustion chambers keeps increasing and gets higher than the threshold. This causes the fuel to ignite earlier than it is supposed to especially when the engine is at low RPM, which can cause a knocking sound. If you are aware of the concept of knocking, then you will know that it is really bad for your engine if it happens for a prolonged time.

  5. Rough Engine Idling

    Rough Engine idling
    Rough Engine idling

    When the EGR valve is stuck in the open position, there is a possibility that it can allow too little or too much exhaust gas into the combustion chamber as there is no control over the recirculation. This again causes an incorrect mixture of air and fuel inside (which ideally needs to be perfect) and cause the engine to idle rough. This is characterized by rattling noises as well.

  6. Smell of Fuel

    Fuel smell
    Fuel smell

    The NOx released from the tailpipe of your car is not only harmful but has a very pungent odour. Also, when the EGR valve is not working correctly, there is a chance that your engine may burn more fuel, which releases a lot of hydrocarbons. They mix with the added NOx and generate a dangerous mix of harmful gases.

  7. Engine stalls while idling

    turbo petrol mileage
    Car engine idling

    An EGR valve when stuck in an open position not only creates rough idling but sometimes causes the engine to stall while it is idling. Now, this might not seem as dangerous as a car stalling while driving, but it definitely hints at a clogged or faulty EGR valve and demands your attention to ensure it does not keep happening.

  8. Check Engine Light ON

    Engine Temperature Dashboard Warning Light
    Check engine light

    A check engine light may appear for a lot of other reasons and not just for a failing EGR valve. However, if the EGR valve finally gives up or stops working, then you will most likely see the check engine light. So, if your check engine light turns ON, and it coincides with the other reasons, it most probably will be the EGR valve. An electronically operated EGR valve gets its instructions from the ECU and the ECU also handles the illumination of the check engine light.

So when you encounter these symptoms provided above it is always advisable to get the vehicle checked by an expert to make sure your loved one do not suffer.

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