[Pilot]

This car was in storage for two years by the prior owner and when it came out of storage, about 600 miles ago, all the fluids, including the coolant, were thoroughly flushed.

If there is a milky substance inside the oil filler cap, is that a guaranteed blown head-gasket or could it be something else? There are no other blown head gasket symptoms: 1) radiator overflow bottle is not filling/overflowing and there is no unusual smell nor any oil residue in the coolant overflow bottle, 2) exhaust does not smell sweet, 3) there is no overheating problem, 4) the oil on the dip-stick looks normal without any detectable residue or unusual color, 5) there are no visual signs of any leaks.