I have a 1995 Mazda MVP 6 cyl. rear wheel drive. I was driving it when I notice that there were no heat coming out, but cold air, then the check engine light came on, I put over and notice the hot/cold grage needle go to hi, and white smoke coming from under the hood. I told the following steps in trying to correct the problem. I replaced the tempstat, water pump, and the radiator, but the problem is not corrected. The engine idles up and down making the RMP grage go up a little. The water in the radiator don't seem to move at all, the Hot/Cold grage goes up to hi. I hope describle the problem. Please let me know what can I need to do next or what I need to check in the engine.

It could be that you may have put the thermostat in upside down or the water pump's not turning. Post back after you've investigated these possibilities.

i replace the water pump with a new one, the thermostat
was put in the correct way. Everything was check before final installation.

It could be due to water freezing in the radiator and engine block causing the engine block or radiator to crack. Do you have a 50/50 mix of water and coolant? Water alone will freeze and cause these things to happen. The water pump seal depends on the coolant to oil the seal. Water alone will not cool the engine!!! Check oil level,coolant level, and transmission fluid level. If the transmission fluid is low it will put more stress on the engine causing it to overheat. If the oil is low, you know how this goes. Post back if you find the problem.

Base on what you saying re: low oil in the engine, tranny, or cooling in the radiator, all these items were ok, and full. I still cannot find what cause the hot/cold gauge to go to hi. I replace the radiator, water pump, and thermostat. I'm wondering if there is an electric valve or something which close and open when it need heat. Or can someone guide me to where the heater hose come out in the firewall.

my mazda mpv is overheating and the heater is not working (and i change already every thing) if you have find out how to fix the problem please email me.

thanks
orlando lazadi

Check the heater core for possible leaks, also check the heater valve for proper functioning. Heater valve lets hot coolant into your heater core.

CHECK IT COULD HAVE HEAD GASKET LEAKING..