Faulty EGR Valve Symptoms and EGR Valve Cleaning

Simply put, the EGR is meant to reduce emissions from the car. It reroutes some of the exhaust gases which are emitted by the engine into the combustion chambers. This effectively reduces temperatures in the combustion chambers. 

The EGR valve is an important component in the exhaust gas recirculation process as it helps to prevent exhaust valves from overheating, which can accelerate their wear and tear. The EGR valve therefore helps maintain the exhaust system at full capacity and increases the longevity of the internal combustion process. 

An EGR valve that is stuck open

When the EGR is stuck open, it will lead to a vacuum leak which in turn causes inefficient combustion, hesitation, rough idling and even stalling. The reason for this is that the car cannot combust on the carbon dioxide emitted from the tailpipe. An open EGR valve causes exhaust emissions to flood the combustion chamber, hence preventing it from functioning as it should. To check for a stuck open EGR valve, idle a parked car with the brake on and have someone examine the plunger shaft to see if it is stick open. 

An EGR valve that is stuck closed

This causes nitrogen oxide emissions to rise and the car might start to knock. A sharp knock occurs when the fuel in the combustion chamber ignites before the explosion in the cylinder reaches it. This leads to a disruption in engine timing. When this happens, warm up your engine and rev it, then check if the EGR valve will move. 

If your car is running poorly, it might be a sign that your EGR valve has a problem. While there is no conclusive way of testing EGR function at home, you can always remove and shake it. If you can hear movement, then your EGR is okay and only needs cleaning. However, if you do not hear any movement, there might be a chance that the EGR valve is stuck. You should always seek the opinion of a professional since it is impossible to say for sure if the valve is damaged. Here’s how to go about EGR valve cleaning that you can do it by yourself.

1. Remove the vacuum line connected to the EGR valve. Should it be damaged, brittle, frayed or broken, replace it.

2. If the EGR valve has an electrical connection, disconnect the harness carefully.

3. Unbolt the EGR valve from the engine. Give it a slight tap if it doesn't come right off. You can use a tiny hammer or a block of wood to do this.  

4. Remove your gasket if it is frayed, torn or disintegrated. You can reuse it if it’s in good condition. 

5. Soak your EGR valve in a bowl of carb cleaner. Avoid submerging the electrical portion if it has one. You should soak it overnight if possible. 

6. After soaking the valve in the cleaner, you should clean the openings, passages and surfaces by using a small brush. You can also use a toothbrush or a pipe cleaner for this. Make sure to have eye protection and chemical resistant gloves because the carb cleaner is harsh. 

7. The final step is to reinstall the EGR valve. Remember to reattach the vacuum hose and electrical connections if you had any.