Volkswagen Workshop Service and Repair Manuals

In order to keep the amount of poisonous nitrous oxides (NOx) to a minimum, exhaust gas is recirculated into the combustion air in the part load range.

Control is by way of a valve which opens and closes as a function of the throttle valve position.

Checking EGR valve

• ◆ Minimum engine oil temperature 60 °C

• ‒ Allow engine to idle.
• ‒ Pull vacuum hose off EGR valve.
• ‒ Pull vacuum hose off retard unit and attach it to the EGR valve.

The system is OK

• ◆ if the idling speed drops off appreciably
• ◆ the pipe - EGR - becomes warm after approx. one minute