I was on my way to work a couple mornings ago, when i look down at my temp gauge and i notice that my truck is overheating. I pull over to the side of the road and call someone for a ride. I go to pick it up at the end of the day and open my rad cap to see if i am low in antifreeze. when i open the cap a huge rush of fluid came out. I decide to drive it home and the same thing happened, started to happen, the thermostat didnt open and i noticed that i had no heat at my heater vents. This morning i pull the truck into the driveway, shut her off, pop the hood and open the rad cap, sploosh fluid all over the drive way. I thought it might have been a big air bubble so i start filling the system thru the heater hoses and i got it full but when i take the cap off its constantly blowing little bubbles. My first thought thought is head gasket, but why am i getting no heat from my heater vents? No water in oil and no white exhaust.

 

Can you start it up when it's cold with no cap on and it immediately and steadily blows bubbles?

If so I would say it's the head gasket.

I had a little turbocharged 2.2 Shelby that does exactly as you described.
No white smoke, no milky oil, no heat but a lot of pressure.

 

My work truck ('05 Sierra 3500 with the DuraMax) is in the shop now getting new head-gaskets after presenting with the same symptoms. Runs just fine otherwise.

You're getting no heat as the coolant has been replaced with the air pocket (gravity drained it).

Sorry.