I searched for this and came up short. I have a Koyo radiator and I had just fushed it and the motor 200 miles ago. I am selling the vehicle and now I decided to check the A/C because it's a good selling point and I had used it last summer and turned it on every once and awhile during the winter. Now the a/c on causes the car to overheat, I just have the clutch fan and not the small efan. The thermostat is not OEM but has been working fine. I might need to recharge the system yet haven't tested the system yet. It blows cold for about 15 min. then starts to blow warm and the engine starts breathing as if there was a vacuum leak. Any suggestions?? I'm going to check it out at the shop tomorrow til friday. Any other ideas and or people who had the same problem I wouldn't mind hearing possible causes, thank you.

 

Is it OVERHEATING? Or just getting a bit warmer than normal? It's perfectly normal for the temp gauge to rise a bit when you're using the A/C...or going up a biiiiig long hill...or driving the car hard.

 

Did the thermostat you get look like the OEM one (stant possibly)? or did it look like a typical boinger thermostat?

 

is the A/C cooling fine? make sure the auxiliary fan is turning on when you turn on the A/C. if not the condenser will get very hot and you will see a difference in the temp.

 

I don't have the aux fan. As for "overheating", yes to the point of the coolent bubbling, the thermostat is a Stant. I was reading one on your polito did you ever fix it??

Once it starts getting hot it just keeps getting hot. The a/c blows cold for the first fifteen then to hot then to low idle with fluctuation aka "breathing", as if there is a vacuum leak. I'm going to try to evacuate the system today.

 

yeah i rewired tha fan and changed the thermostat. but I dont have A/C so its a totaly different story. Im sure if you get the auxiliary fan worknig your problem will be solved.

 

aahh it's cause your using a stant thermostat, only use MAZDA thermostats, thats the problem.