lASTWAGEN11

How does one know if their Oil Separator (642 010 1691, aka Pressure Control Valve or Bleeder Valve by some) needs replacing or is still good after 77K miles?




My E350 BT Clean Air Duct has a port for the Oil Separator hose, right before the Turbocharger inlet port gasket (Orange). The other end connects to the rear right side engine head, where it is exposed to the engine internals. I figure the Oil Separator functions to release any internal engine pressure by venting oily vapor back into the intake flow. Not sure here, only an educated guess on my part.



Is that right?

So does that Oil Separator have a pressure valve, to control vent/no vent? Seems to me that the Oil Separator must have some control point to regulate engine vapor flow; is it always open? Or does it just close the venting when there's high negative pressure (like from the turbo intake)?

There is an electrical connection at the outlet end of the hose, but I'm not sure (I really don't know) what function it has. Its probably a temp sensor of sorts; internal to the hose, last 2 inches is a copper pipe, with a D section. The piece is molded plastic with the electrical connection (2 pins) on the flat spot of that D pipe. What is it for?

So, is it good?, or how to tell if its still good?