We own a fleet of Ford E series vans years vary 2000 to 2013 all of them have moisture that builds up between oil changes under the oil caps. I was told that this 1 or 2 things that we do that causes this. 1) We have never had the PCV changed on any truck since they were bought new. 2) We have a idling policy that requires our driver to shut the truck off and restart at every delivery. Each delivery takes about 1 to 2 minutes each. And more time than not the locations are 2 to 10 miles from each other. each route has between 40 to 60 stops each night. Is what Im being told true and can you explain to me why this happens?