So I did an oil change about a week ago and the next morning after driving maybe 10 miles I open up the oil filler cap to adjust my oil level to find milky white residue under the oil cap. My first thought was that there was just condensation in the block and it didnt have time to fully burn off since I hadn't driven that far. By the time I finished my drive which was about another 100miles the residue was gone. Every day for the past couple days I have had the same residue under that cap. I am really worried that I have some leak somewhere. I have pressurized the coolant system but am not really sure how to interpret the results. The radiator cap says 88kpa or about 12.7psi so I pumped it up to about 13lbs and after two hours I was down to 7psi. This could be from a leaking tool but it could also mean a number of other things. Anybody have an opinion on this or has anyone experienced the same type of thing. Truck seems to run fine and I have not noticed the coolant level go down besides normal fluctuations. It has been really cold here (frost every morning) which has not been the case until recently so that is why i suspect normal condensation in the block.