March 21, 2014

Hi guys I`m new on this site and am at my wits end.the problem is twice my 06 f250 5.4 eats all of the oil in the motor and leaves a milky residue in the oil fill cap. No water in the oil pan and no oil in the water. No oil leaks and no smoke. Pressure tests come back fine
So any ideas what to do next. Thanks