I suspect what you are seeing is water vapor from the vents condensing outside the engine, but you shouldn't smell any of that when you are driving. Usually any smell of oil while driving is from a leak. Have you looked for leaks? The valve cover is a good place to start looking, and also the side cover. If you see vapor condensing from the road draft tube when the engine is stopped, I don't think the tube is plugged, but it is a good idea to check/clean it. If there is concern of ring wear and blow-by, do dry and wet compression tests- an increase on compression pressure more than 20-25 PSI indicates ring or cylinder wear.
Harvester
