Exhaust-gas recirculation system
The exhaust-gas recirculation system (EGR) enables a reduction in the nitrogen oxide emissions, while at the same time reducing the fuel consumption. This is achieved by a lower combustion temperature and reduction of the gas-exchange losses as a result of the exhaust gas recirculation. The electrically controlled valve requires neither an additional solenoid coil nor vacuum hoses. The EGR valve of the R50 has a unique pressure compensation function. This pressure compensation function reduces the influence of pressure fluctuations on the valve, thus enabling the use of a smaller solenoid coil. This feature contributes to evening out the function of the valve across the entire vacuum range.
The EGR valve can jam in two different positions: in opened and in closed condition. Jamming in the opened condition influences the idling quality. In the closed condition, the engine can knock under load. The possible influence on the exhaust emissions can lead to activation of the MIL.