Hello
I have a crown victoria 2005, yesterday after turning on the car within 5 minutes a white smoke or like water vapor comes out of the air vents " the AC is off " it doesn't have any smell to it.
and when I check the radiator water its less.
Sounds like what mine did when the heater core blew, but it had that sweet smell of antifreeze which unfortunately I've become very familiar with. Depending on the size of the leak it may be just enough to create a vapor but not enough to really look like the radiator is low. I've had both kinds of leaks. One that's fills the floor board with antifreeze and the other that just create a little vapor.