Good evening. A new dilemma has popped up on my 2012 C250 (1.8 Turbo). After replacing the o-ring at the upper end of the turbo oil line, I still have the very slightest of oil leaks (barely oozing). I think I have located the spot, but I do not know what I am looking at. Near the top of the attached picture you can see the small cylindrical riser with a strange flange in the center. This is just in front of the exhaust manifold and just below the head. It is slightly below and to the rear of the turbo oil tube connection at the head. Can someone suggest what that is and if oil can ooze from it.
Thank you again.
RG

The part in question is just in front of, and below the exhaust manifold (foreground). upper center of the picture. The silver riser with the flange in its center.