CM 871 compressor

[Wiseman]

I’ve seen worse. This is what EGR soot does to everything.
If you can’t live with it pushing little to moderate amount off oil to your air dryer, you have to replace it . That’s the only option and right way . Make it right .
When unloader is open the piston pushes air back and forth on intake side and oil can go there. So don’t freak out.
Almost forgot. The blow by and crankcase pressure helps a lot for oil to get true the scoring on top off piston.
The good thing is , you found the source for coolant loss . So you can sleep better.

Just a reminder. Torquing sequence and torque is crucial when installing head .