does the heater work when the gauge is showing 100degrees?

Have not tried. What does that do?

Air should come out real hot and help cool the motor- its just an extra radiator.

in a ke30/55 the top heater hose is the 2nd highest part of the cooling system.

 

with my blown headgasket 5k. (exhaust gases in coolant) temp would rise to 100 degrees till the thermostat would open the heater would all of a sudden get cold, cause all of the water out of the heater core was getting pushed out.

 

pulled the water pump off? tried running no thermostat?