What is an EGR?

EGR stands for exhaust gas re-circulation, it is an effective method to control Nitrogen Oxides (NOx) emissions produced by petrol and diesel engines. The EGR is often located on the inlet manifold of the engine, however sometimes it can be located further down near the exhaust manifold. The EGR system works by recirculating a portion of the engine’s exhaust gas back into the engine cylinders, this lowers the combustion temperatures which results in a reduced amount of NOx being emitted.

How does the EGR system operate?

When the EGR valve is open exhaust gases are able to go through the EGR system to help manage the car’s emissions. When the valve is closed the exhaust gases aren’t able to pass through the EGR. The EGR valve is closed when the engine is first started and as the vehicle begins to speed up and the engine reaches its operating temperature the valve will slowly open. When the vehicle is slowing down or comes to a stop the EGR valve will slowly close. EGR System

Why could the EGR system fail?

A faulty EGR valve can cause issues with the operation and maintenance of the EGR system, resulting in other issues through the vehicle. EGR valves can become forced open or closed because of the build up of carbon deposits, soot particles and dirt from the fuel. 

Symptoms of a failing EGR system

1. Vehicle producing more emissions

If the EGR system isn’t operating correctly more emissions will be released. When the valve is stuck open the temperature is lowered which will cause less efficient burning of the fuel. This will result in an increased amount of unburned hydrocarbon gases coming out through the exhaust. If the EGR valve is closed the temperature is higher in the combustion chamber allowing excessive formation of NOx gases.

2. Engine performance issues

A congested or failing EGR valve can disrupt the car’s air fuel ratio, which can result in engine performance issues such as a reduction in power, acceleration, and even fuel efficiency.

3. Rough idle

A very common symptom of a failing EGR system is a vehicle’s rough idle. When the EGR valve is stuck in the open operation it can cause a continuous flow of exhaust gases into the intake manifold. This will result in a rough idle and sometimes even cause your car to stall while idling.

4. Check Engine Light comes on

When there is an issue with the EGR valve position or circuit it will set off the Check Engine Light to notify the driver of the issue. The Check Engine Light can also be an indication of a variety of other issues, to correct the issue it is highly recommended you the computer scanned for trouble codes. Check Engine Light

5. Knocking noises coming from the engine

If the EGR is constantly closed it can cause knocking sounds from the engine. This is because at low rpm the fuel ignites early when it meets the high temperature.  

6. Increased fuel consumption

When the EGR valve is stuck open the temperature is lower. Therefore the fuel doesn’t burn at the ideal temperature, which in results is less efficient and goes through more fuel.


Replacing EGR valve Hamilton

If you’re having any EGR carbon problems or needing a diagnostics scan than Grimmer Motors has you covered. Our expert mechanics can quickly find what is causing this problem. We can then provide honest, expert advice, servicing and repairs.

For EGR system Replacement in Hamilton, contact Grimmer Motors today!

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