Okay, guys, please be patient with me. I have a 94 mazda protege that just started overheating on me. There is also nothing but cold air coming out of the heater. I put a 50/50 mix of antifreeze and h2o up to the fill line in the plastic reservoir and it hasn't changed but my temperature soared today! please help me figure out what is going on. Thanks in advance.

 

Things could be plugged up somewhere, but it's probably the thermostat sticking = needs replaced.

 

Okay, well i thank you for responding!

 

I dont know about the mazdas, but i know the toyota celica heating is always working. While the car is warming up. the heater will put out warm air whilt the thermostat is closed. No water is flowing through the radiator while water is constantly flowing to/through the heater core.

Mine had a heating problem recently to. I was driving and i looked at the dashboard at it was at hot. So i pulled over and let it cool. So i started it and put the heat on high, and the heater was putting out extremely hot air. Put new thermostat in and no more overheating.

If the heating and cooling design is the same as my toyota then you would have heat while overheating. I dont think you not having heat would make it over heat. But if the heat was working then you know your water pump is good.

So you probably need a new thermostat like bob said and you might have something plugged up around the heater core or the switch that allows the water to flow to the heating core (heating switch i think.

 

If the heating problem is hit or miss I would have to say you have air in the system. You need to bleed all the air out of the system. What was the reason you filled up the resevior? DId it run dry?

 

The resivoir was filled, But do you have anything in the rad?? After the engine cools check the rad level & also check the belts for cracks & tension.