Exhaust Gas Recirculation System

The exhaust gas recirculation system reduces the emission of highly toxic nitrogen oxides. The supply of part of the exhaust gases together with air into the engine cylinders causes a decrease in the boundary temperature of the combustion of the fuel, which has a significant effect on the formation of this very undesirable component of the exhaust gases.

In a non-turbocharged engine (1.8 D) this system includes:

• thermal switch with vacuum servomotor. located on the thermostat housing, which turns off the exhaust gas recirculation when the engine coolant temperature is below 60°C;
• vacuum control valve located on the fuel pump;
• vacuum limiting valve;
• exhaust gas recirculation valve. located on the intake manifold of the engine, which, under vacuum, opens or closes the connection between the exhaust manifold and the intake manifold In a turbocharged engine (1.8 TD) the exhaust gas recirculation system is controlled by an electronic control device and includes;
• coolant temperature sensor located on the thermostat housing;
• solenoid vacuum valve located on the left front side of the engine compartment, this valve is exposed to the vacuum generated by the vacuum pump, the solenoid valve receives a voltage signal from the electronic control device and makes it possible to supply vacuum to the EGR valve servomotor;
• under vacuum, the diaphragm of the EGR valve servomotor causes it to open. allowing the flow of exhaust gases from the exhaust manifold into the intake manifold.