My 97 dually had been parked for several days while I was attending a class. Had been really cold during the day and in the teens at night. Started her up when I got ready to leave and it puked oil out the drivers side of the engine somewhere. Didn't crawl under to look because only about a cup or two (looked like) ran out. After it had ran a few minutes it stopped. When I shut it down and started back up during the trip home it didn't happen. Only thing that changed is I plug the truck in at home to be easy on cold morning starts and it wasn't plugged in this time. I'm sure something is screwed but what is it?