Hi, I have a 1994 Ford E150 Luxury Conversion van with 85,000 miles. It has the 4.9 Liter (300 cubic inch) inline 6 cylinder engine. When I use synthetic oil, the oil foams during the 1st 3,000 miles of use on that oil. Then the foaming stops. I notice the foaming when I remove the oil cap. I see white foam on the side of the oil cap which faces the engine. The 1st time this happened to me, I switched back to dino oil and the foaming stopped. Then, I switched back to Mobil 1 Synthetic, and sure enough the foaming started again. I'm currently on Mobil 1 Synthetic again, and the foaming has again stopped after 3,000 miles on the Mobil 1 oil. Is this oil foaming by synthetic oil for the 1st 3,000 miles a bad thing which could be resulting in some poor lubrication? Has anyone else had this oil foaming problem when using Synthetic oil? Thanks, Bill