DHB,
The OM616 is not turbocharge so there is no ALDA. I think there is a device called a ADA which only compensates for elevation change. There is no boost line heading towards the IP or switch-over valve since there is no boost. But, I agree with Rick, this sounds more like the EGR valve. It may be time to upgrade it with a specialized metal gasket without the large hole in the center.
That hole in the current one tends to let exhaust gas into your intake
