Nowadays, the Exhaust Gas Recirculation (EGR) valve is a part of almost every diesel engine. The EGR valve function allows diesel engine exhaust emissions to be reduced while also reducing fuel consumption. It is a device that returns a measured amount of flue gas back to the engine intake unit, and thereby lowers the combustion temperature by reducing the amount of oxygen in the fuel mixture.
This component has been installed in cars with the advent of the Euro 3 emission standard. Since the introduction of EGR valves, their system has evolved, and therefore almost all parts are now controlled electronically by the main engine control unit.
The soot buildup is the biggest problem causing the EGR valve system to fail. Soot mostly end up in the flap through which valve regulates the amount of exhaust gas that goes back into the engine. Excessive amounts of carbon in the EGR valve can be caused by long-term vehicle operation at a lower acceleration value when the valve chamber becomes carbonized. In the case of failure of this component, a slow onset of symptoms can be observed until a final failure. All of this is due to the slow deposition of soot and disabling motion of the EGR valve flap. In some cases, the flap may remain open or become stuck and may cause damage to the engine intake
Signs of this defect are for example:
- black smoke coming out from the exhaust
- occasional engine jerking at higher acceleration
- idle fluctuation
- Impossibility to start the engine
Given the scale of this component, the possibilities of its remanufacturing have expanded. The EGR valve is remanufactured by thorough cleaning by the means of pressure or chemical compounds. The entire valve component is thoroughly disassembled and cleaned, then assembled by qualified personnel, and finally tested at a certified location. They are tested by vacuum and / or ECU stimulation.
When replacing the EGR valve, make sure there is no dirt in the engine intake system and use a new gasket for the remanufactured part.