Vacuum (Intake Pipe Pressure) Controlled EGR (Retrofitted Exhaust Gas Recirculation):
At idle speed, connect manual vacuum pump MKM-667 to valve and create a pressure difference of approximately 400 mbar.
Idle speed must be significantly reduced.
For exhaust gas recirculation (EGR), we differentiate between mechanical and electro-pneumatic exhaust gas recirculation pressure transducers.
Mechanical Exhaust Gas Recirculation
Detach vacuum hose from exhaust gas recirculation valve. Generate pressure difference in exhaust gas recirculation valve using vacuum pump.
Visual check: Does the pin move
Electro-Pneumatic Pressure Transducer for Exhaust Gas Recirculation:
| Vectra-C: | Y 20 DTH and Y 22 DTR |
|---|---|
| Zafira: | Y 20 DTH |
| Corsa-C: | Y 17 DT |
Valve, Exhaust Gas Recirculation Z 13 Dt DOHC Diesel Engine, Y/z 19 Dt Ohc-Diesel Engine and Y/z 19 Dth DOHC Diesel Engine
The exhaust gas recirculation system of the Z 13 DT DOHC diesel engine, Y/Z 19 DT OHC diesel engine and Y/Z 19 DTH DOHC diesel engine has an exhaust gas recirculation valve located on the intake manifold.
The exhaust gas return valve is triggered electrically by the engine control unit and permits precise regulation of the amount of exhaust gas supplied. The exhaust gases of the exhaust gas recirculation system flow from the exhaust manifold via the exhaust gas recirculation pipe through an exhaust gas recirculation cooler. The exhaust gas recirculation cooler then routes them via a further exhaust gas recirculation pipe to the exhaust gas recirculation valve.
In the Y/Z 19 DT OHC diesel engine the exhaust gases are routed into the intake manifold via the throttle valve module.
In the Z 13 DT DOHC diesel engine and Y/Z 19 DTH DOHC diesel engine the exhaust gases are routed directly into the intake manifold. In the intake manifold the exhaust gases are added to the fresh gases supercharged by the turbo-system.
A reduction in the quantity of oxygen is achieved by adding a controlled amount of recycled exhaust gases to the fresh gases. This leads to a reduction in the combustion temperature in the combustion chamber and thus to a reduction of the nitrogen oxide concentration of the exhaust gases.