When I left work yesterday afternoon, the temperature was down around 10 degrees. I have always ran 30 weight high detergent oil year round in all of my air-cooled VWs, but this is the first time I've ran one with it this cold outside. About 4 miles down the road I started smelling oil burning and looked in my rear view and saw nothing but smoke. I pulled off at a Golden Gallon and popped open the deck lid . . . the entire engine compartment was soaked with oil. It was a quart low and in the couple of minutes it took to buy and add a quart a big puddle had formed under the car. There was so much oil that there was no way to tell exactly where it was coming from. I headed on to the house and stopped in Noble (about 4 more miles down the road) and added another quart . . . it was still slightly below the full mark, and I didn't want to have to stop and add oil again (it was just too d*** cold!!!!) so I went ahead and overfilled it by adding another quart. It was a little below the full mark when I got home. So, in all I lost 3 quarts of oil in about 13 miles. I'm not sure, but it looks like it might be coming from the oil sending unit.
My thinking is that at 10 degrees, 30 weight is about the consistency of STP oil treatment on a warm day. I think it just built up more oil pressure than the sending unit (or the oil cooler, oil cooler seals, oil pump cover gasket, or whatever turns out to be leaking) could take. That's just a theory . . . and I'm not too fond of the idea of trying to prove it right or wrong until the weather warms up . . . but I'm sure going to consider going to a lighter weight oil during the winter from now on.
