Take a look at the driver's side engine pic at
viewtopic.php?f=98&t=74594 .
Comments, at least I think I have it right:
1. the copper looking pipe on the right runs from the exhaust manifold to the EGR valve.
2. when the EGR valve is open some quantity of exhaust gas is diverted thru the valve, EGR cooler below it, to the heat shield wrapped bright (ss looking) pipe that runs to the intake elbow, and on into the intake.
3. when the EGR valve is closed (actually when it's open too but I don't think that matters as much given what you are looking for) intake air with appropriate turbo boost comes from the driver's side CAC hose to the FCV (flow control valve - rectangle with notch on upper left in center of picture) and then up to the intake elbow (thing the pipe in #2 attaches too)
4. intake air coming from the turbo carries a certain quantity of oil from the CCV (hockey puck looking thing on top of the engine with hose running to the air filter box to turbo hose just in front of the turbo)
5. assuming some degree of boost pressure some of that oil can escape (drip) from any of several joints along the path from the CAC hose attachment point mentioned above including both ends of the pipe mentioned in #2 above.
I'd suggest you get the engine slightly warm, spray that side with a good engine degreaser, rinse lightly with water (not hard enough to get water into electric connections), drive a bit and see if you can spot exactly where the oil is coming from. I'd suspect a leaky gasket although the marmon flange where the pipe in #2 above connects is a good candidate. Solution - tighten loose connections, replace gasket, use appropriate RTV depending on where the leak is actually located.