So my coolant overflow is always about 2" below the "cold fill" line.
If I top it off, and drive for an hour, it is back at 2" below. But won't go lower...

I blow what I think is a lot of white smoke, and get water dripping out the tailpipe.

I figured bad head gasket.

I put a bottle of Bar's Leak head gasket repair (part number 1111) in the overflow tank, and that bottle brought coolant to about an inch above the "cold fill" line.

I've driven for a couple days, and the level in the coolant tank hasn't changed.

Why isn't the leak stop moving into the coolant system?

Any what stops the pressure in coolant tank from escaping the overflow tube on the neck of the tank?

 

its condensation, when you shut you truck off when you come home, the Humid air goes into the muffler and makes water/moisture, when you start up the truck in the morning, it has water coming out and white smoke, white smoke is heated moisture from the engine heat...
really seen and noticed on cold mornings....

if you had a blown head gasket, you would have either coolant purging out of the tank or going out the exhaust, and your tank would be low...( Daily )
Best way to see if you have a head gasket leak is to have the tank pressure tested....

so far, I am on my 3rd Radiator, the heats a Killer here in south Florida

2004 H2
2006 H3

 

Another way to see if you have a blown head gasket is to check your oil dip stick. Pull the dip stick out ,wipe it off good. put it back in. Pull it out. if you drops of water mixed in with the oil ...your gasket is leaking coolant into your engine block… Not good at all. Looking at possible wrapped heads, rusting main bearings No not good at all.