Hello guys! new here, Recently got my 8 with a brand new motor in it (from mazda) about 3.5k miles ago. While driving around for an hour or so in stop and go traffic, My water temp on my aftermarket gauges started climbing to around 238 degrees! I pulled over, Let it cool down, and now to this day if i drive with the AC on my water temp climbs if im not careful (way faster if im driving but slow steady increase when im parked) If i turn off the AC it cools back down once i stop the car at stoplights and whatnot. This is really racking my brain, any help would be amazing. Thanks guys!

Ive also verified that its not my aftermarket gauge, Checked with scanner as well

Ive replaced:
Thermostat, Radiator fans, and Radiator.
Other things ive done to try and fix it:
Burped the system every time ive drained and replaced the coolant, Installed a fan controller, and i am currently running 70/30 coolant.

 

Do you still have the engine undertray below the radiator? You really need that to direct air to the radiator at speed.

A/C condenser is right in front of the rad, and produces heat when A/C is on.

 

Yes i do still have it, could my condenser be bad? I still get Ice cold AC and hot heat

 

Your condenser is fine. If it's making heat, it's doing it's job.

How's the coolant overflow reservoir? Is it holding pressure? They tend to get brittle with age and crack around where the rad cap sits. Examine it thoroughly.

Are both fans activating? If the second fan, which is supposed to activate when A/C is turned on, isn't turning on then you would have symptoms like this.

So here's the other thing: you engine has been overheated, which is not great for rotaries. If the overheat compromised the water seal, it's like blowing the head gasket in a piston engine. It could cause the car to run hot and overheat. I would test your coolant for exhaust gases.

 

Will do, I examined the coolant reservoir and it seems to be good, Ill get it tested.If anything im having mazda diagnose it next week.