At the end I removed the head and found this!
I believe this happened because of air bubble in the cooling system, I drived for a while at too high temperature...
But now I want to solve rapidly this misadventure!
I' ve a complete M104981 ready to be mounted.
I should mount the complete engine in my garage and don't have a hoist!
Considering this could please someone help me by telling me if Is better to leave the trasmission at its place or removing all together?
If don't removing the trasmission I need to drain the oil or it remain inside when decoupling it from the engine?
Thank You