My Ranger 2005, V6 4.0l is using coolant for some reason. Checking fluids yesterday I found the overflow tank empty and the radiator down about 2in. Looked the engine compartment over no obvious leaks. No drips on concrete, felt the carpet on passenger side dry as a bone. Checked the oil full no water. I topped off the radiator and filled the tank a little over 1/2. Drove about 25 miles checked the coolant tank was about 3/4 full. Visted my brother for a while and when, and I started the truck a film of condensation coated about half the windshield. Disappeared 30 seconds. The condensation has happened a few times in the past. I'm thinking maybe something to do with the heater core or that system. I've read up on changing the heater core not fun requires dash out. So I want to be sure if possible. thx

 

On a 4.0l SOHC engine the most common leak point for coolant without dripping to the ground is the thermostat housing, it is in the front center of engine, its plastic and cracks or just leaks
You can get a metal replacement housing now, if it does leak and needs to be replaced
Thread on that part here: https://www.therangerstation.com/for...pgrade.188702/

Leaking heater core will cause water vapor on the windows but will also have a distinctive sweet smell that coolant has when heated
The vapor on the windows can also be caused by blocked AC evaporator drain hose, the hose that drips water in the summer when AC is on more, comes out the firewall under the heater/AC box
Or can be caused by general humidity in the outside air certain times of the year

So no smell when you see the vapor means its not coolant that leaked into the cab