Can anyone explain this?
Took the King Ranch to the dealer last week for a charging problem, sure enough the alt had low output and was replaced. While it was there they checked out an oil leak and found the pan bedrail seals leaking, pulled the engine and replaced the seals (all under warranty thank goodness) and away I went. At home I decided to replace the thermostat which I had suspected was stuck open. Opened the radiator drain valve and removed the cap, the radiator seemed to be draining slow so I opened the valve a little more and WHAM a burst of air came out that sounded like a shotgun blast and blew the funnel out of my drain jug, replaced the thermostat that was stuck open by the way, refilled with coolant and all seems fine. Just can't figure out where that slug of compressed air came from, any ideas?