An exhaust gas recirculation valve (EGR) is used in all diesel engines from Euro 5 onwards to reduce nitrogen oxide emissions (NOx). This is done by recirculating hot exhaust gases into the engine's intake duct. This lowers the combustion temperature in the engine and reduces the generation of nitrogen oxides.
The major disadvantage of exhaust gas recirculation is the technical vulnerability of the EGR valve, which regulates the supply of exhaust gas into the combustion air flow. With exhaust gas recirculation, fuel residues such as soot, oil carbon and unburnt oil enter the intake tract and can restrict the mechanical mobility of the valve or clog the pipe bends. The result is malfunction of the EGR valve, which can lead to heavy soot generation, reduced engine performance or engine damage.
To avoid serious damage to the engine, the EGR valve should be cleaned in good time. In this case, fuel additives or spray cleaners cannot provide any remedy for valves that are already dirty due to the stubborn encrustation and the valve must be removed. In the ultrasonic bath, effective and thorough cleaning takes place together with a suitable cleaning concentrate. Depending on the degree of soiling, prior manual removal of coarse soot agglomerates with plastic or wooden spatulas is recommended. After residue-free cleaning, the valve can be used again and high replacement costs are avoided.