Yes, probably the crank case breather hasn't been changed as Mr Buckshot states.
It needs changing every service, but if it hasn't, the inlet carbons and oils up until the damn thing chokes itself to death and oil exits the engine via the dip stick.. The EGR helps with the oily build-up as well.
The crank breather element needs replacing, the inlet manifold needs steam cleaning and you should probably think about an EGR blanking and an oil and filter change. Add in an intercooler flush as well.