I need help identifying a part on my 300D. It is a 1981 NON turbo. I need to know what the part is that is on top of the IP in the same location as the ALDA would be if it was a turbo. It has what looks like a vacuum port on the side, but I don't know if it needs to be hooked up to anything. When I first got the car, the hose from the windshield washer fluid resevoir was hooked up to the port, and the resevoir was filled with green coolant (yes the PO was that stupid aparrently, not the only issue like that I have found.) Just trying to get this thing roadworthy for the wife. Any help appreciated.

That is the ADA, it is an altitiude compensator. The port should be open to the atomosphere.

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

That is an atmospheric VENT port...nothing is to be connected.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Perfect, that is exactly how it is right now. Thanks!