My car just started overheating tonight and it filled the overflow tank would that be the thermostat? Also if i drive above 40 it cools down adn the heater works if i stop it heats up and the heater blows cold.

 

If it overheats when stopped and cools down when you move, you have a bad fan clutch. Go to a junk yard a get another, as mazda rapes you for new ones.

 

why would it throw the water into the overflow the overflow is way full.

 

Its not the fan I think its a coolent seal.

 

Check to see if the tube to the overflow tank is in good condition and sealed up. Mine was doing the same thing when I bought it, turns out the nipple on the filler neck was busted and the tube wasnt sealing properly

 

yeah i was thinkin it might be the cap because i can hear a leak, i was overheating the it just fixed it self and sucked the water back in and now its back to overheating and dumping water.