The heat comes and goes but mostly is gone. Replaced thermostat and flushed heater core temp gauge is steadily at 195 and both hoses going in and out of heater core are hot. When the heater core was flushed and bled i had heat for about and hr then it was gone. I had someone else bleed it even more just to make sure all the air was out and the heat worked until I got maybe 2 blocked up the street and was gone again. My dad took it for a ride last night and floored it a couple times and eventually the heat came back and stayed most of the day today. Now it is gone again :( Please any advice would be greatly appreciated I live in Michigan and 2 kids we are tired of freezing because these mechanics I know cant figure it out! My dad is trying to say I have a leak in my ibtake gasket but I am not losing antifreeze or any other fluids. Honestly I just think there is still air pockets in the system. Please help thanks!!!!