X 15 565 black oily residue

[2328996abltd]

I got an x15 9000 hrs deleted at 140000km.
It’s has been on and off. Putting a black oily fluid coming from back side of turbo . Also coming out from the manifold where it joins together. It runs ok. Doesn’t go through coolant maybe a little bit once every few months. Doesn’t use any oil. Only does this when is cold especially if I idle it during cold nights -35 or more. No check engine lights or anything. Had valve set done. Any idea as to what it could be.