Nah, the head doesn't have to come off to fix this. Just the front cover of
the right head.
The Main PCV suction line is connected to a poorly designed oil seperator in the front cover. Crankcase fumes are sucked in (with a ton of splashed oil!)
directly behind the cam sprocket and chain. There is a BS little drain shaped
like a boat anchor to drain off all the oil.
The problem is, the drain gets plugged and oil quickly overwhelms the oil
seperator. The PCV system is then free to suck pure oil up into the second oil seperator in the valley of the block and then into the throttle
actuator to dispense it into the manifold and combustion tract.

Easy fix to clean and good service will prevent from occuring again.
Dr.D

__________________
Dr.Diesel -
Shop Foreman
Master Guild Mercedes-Benz Technician.

Think the dealer is expensive? Do you know how much it costs to train a dealer tech? Or buy the required MB special tools to have on hand?