I have a 2005 Honda Civic with the 1.7L engine. Did some work on the car for my cousin cause it was overheating and found the water pump was leaking. So replaced the water pump and while bleeding, we noticed that it had a hole in the radiator as well. So it got a new radiator and thermostat as well. Well while bleeding it after replacing all of that, it had lots of air coming out of the bleeding funnel that increased with rpm so that lead us to replacing the head gasket which I found out was a common issue on this engine. Took the head to the machine shop and had it checked over and resurfaced. Got the head back on and started attempting bleed it again and this time it was violently spitting coolant out of the bleeding funnel which I though was possibly just a bunch of air bleeding out at once however after letting it spit for a little bit, I pulled the thermostat housing off and removed the thermostat and started the process again. This time it stopped spitting coolant out and got heat in the cab. So I'm at a loss as to what the issue could be based on these symptoms now. Should also mention that each time it was bled the heater was on all the way and it never got heat until the last time. The temp gauge never showed that it was overheating either it was in the middle the whole time. Also, the cooling fans are not kicking on and the only way I can get them on is to bypass the temp sensor for it with a paperclip. The temp sensor for that was also replaced.

 

To rule out further head gasket leaks or cooling system leaks you could,

• Use a pressure tester to pressurize the cooling system with the engine not running to see if it holds pressure (isn't leaking somewhere)
• Use a combustion leak tester to verify that exhaust gasses are not getting into the coolant - the pump things with the colored liquid.

If both of these tests pass - then there shouldn't be an issue I can think of that would cause additional air bubbles/spurting of coolant. Maybe some kind of blockage in the system could cause some strange symptoms like that?

It's possible that the block surface was not cleaned enough, or had debris on it when you installed the new head gasket, and it can't seal well?
Could be the head bolts were not torqued correctly (sequence/torque specs)? I believe they are one-time-use bolts too. I went to ARP studs after my first head gasket failure.
Unlikely case, but also could be the block is warped, causing a bad seal to the head gasket..?

Temperature sensors generally only "work" when they are submerged in coolant. For example, if you ran an engine without any coolant - your temperature gauge wouldn't read correctly - as it's intended to measure the coolant temperature, not the 'engine' temperature.

I've never used any kinds of bleeding funnels or special technique to bleed my cooling system, just fill it up and check the level.