Overheating Problem in 01 T&C

My 3.8L T&C started overheating towards the end of a 60 mile trip. Temp guage went to redline in cool weather. Tried turning on full heat but it only blew cold air. Changed thermostat but no change. From a cold start it took about 3 mins of easy driving to reach redline again. Drove it back home (going against everything I know about overheating and because I didn't care at that point) and it was redline about 90% of the way but no obvious problems like leaks, engine sounds, steam or white exhaust smoke. Did hear sounds coming from under the dash like in the heater area like maybe some gurgling and definitely the sound of water.

Took it to the shop and they say it's probably a cracked head gasket or head. They said there is evidence of high pressure in the system given high carbon dioxide levels in coolant. But given that I was able to drive it some 60 miles home and then back to the shop ten minutes without any of the usual and obvious other signs I'm slow to believe it's the head. I'm thinking maybe air is trapped in the system. The guy at Advance Auto said maybe a collapsed heater hose. Anybody have any feedback on what the hell this might be before I go throwing big $ out for this? Thanks in advance.

You don't mention if the fans are coming on like they should . Fans actually should come around the midpoint on the guage . Coolant good ? Check boil point with a coolant checker .

If you had a cracked head leaking into the cooling system, you will see bubbles coming up in the overflow tank when the car is running at full temperature. One way to prevent trapped air behind the thermostat is the remove it and drill a small weep hole in it to allow air release. To check for combustion gas in the coolant, get yourself a Universal Block Tester and check it for yourself. Any good parts store will have one. One more thing, if the thermostat is the problem, the radiator will cold to the touch while the engine is hot. You should also check your coolant temperature sensor to make sure it is not faulty and giving you a false reading.

sounds like a pump if your not getting any heat out of the vents. you may have blown a head gasket because of over heatting it

The fans both come on but the driver side blows only slightly warm air and the passenger side blows cold. The driver side I believe is the return side so that would make sense. The coolant mixture is now pretty diluted with distilled water cos I refilled with that after replacing the thermostat.