Cranking the motor
w/o starting may just suck in some moisture. I would think that residual diesel fuel
would be oily enough to keep the cylinders dry through the winter.
In winterizing my diesels I;
Close the raw water
Run fresh water
thru the raw water
system (I have a T-fitting set up).
Pull the water
pump">raw water pump impeller and drain out any external water that I can.
Drain the wet lift
And, I keep a 100 watt light bulb burning next to the motor
to keep it dry.
Keeping the whole inside of the boat dry is the best thing one can do for winterizing.
If the motor can not be kept dry, like an open decked power boats, then spraying them down with WD-40 helps to keep off corrosion
manual says to pull the injectors and squirt in motor oil
, crank over and reinstall injectors. But I've never had to go that far. Maybe if I were to store it for years, I might go to that extreme.
Different strokes for different boats.