Moin, now I already want to read a lot about the AGR but specifically to the old D5 know what Sasche is. The basic principle is clear, a actuator dosed in the valve exhaust gas via a cooler and mixer to the fresh air flow to regulate the pollutant values. Aaaber: When exactly does it start? When is it in action? Always? Or only at full gas? Or only at partial load? Is there a characteristic speed range? Here in the forum there is a guide on how to clean the mixer. OK, is clearly sow just how does this sample piece of oil get into the mixer? The airflow comes from the air filter, is put under a lot of pressure in the turbo and then already through the mixer. How can there be oil in it? Vlt can split it up for me. Thanks, Lg Jörg