The cowl vent may have something to do with it, depending on how much water gets in. And how much water gets on the truck.
My 58 would get the oil milky between changes when my grand dad drove the truck. But he never really worked it, just a short trip here and there. So the engine never did really get hot enough to boil off any condensation that built up.
When I started driving the truck, I put it to work. It worked for a living and so it got hot and stayed that way for a while each day. I also put a vented oil fill cap on it so the vapors could get out of the valve cover. Mine didn't have slots in the cover.
I also took the road draft tube off and cleaned it to make sure it could provide ventilation for the engine.
I don't know if any of this applies in your situation, but if the cowl drain is letting the water come down on the valve cover, and run into a slot for ventilation, then it wouldn't take a lot of moisture to get the milky look , especially if the engine is only ran for a few minutes at a time.
And the road draft tube is on the passenger side of the engine.
No bubbles is a good sign, and the rusty color may be the rust coming loose in the water passageways.
Last edited by Roy Rodgers; 10/05/2011 10:45 PM.
