onecrazyfoo4u

Today was freaking hot, almost 110 degrees out. I monitor my car with torque app and an ecu elm Bluetooth. Twice on my way home it hit 240 degrees coolant temp and the car shut my A/C off. It would come back down after a minute or two and A/C would turn back on. Is this supposed to happen? I imagine to prevent overheating?



My car was running around 230 coolant temp the rest of the day and intake temps were 140-150 the whole day. Does this seem really hot to you guys? How do I get the temps down?

Red Raspberry

Sounds like it is normal fail safe behavior. You need a bigger radiator or the cooling fan is not working as it should



And make sure the cooling fan is working. On my 2010 Genesis Coupe only the low speed fan is for cooling. The ECU only turns on the hi speed fan for the AC pressures.



This is a big fail on programming because if the lo speed fan resistor fails then the ECU cannot control the fan for engine cooling.

onecrazyfoo4u

Yeah the fan is definitely working, its really loud when I'm sitting at an idle. I'm wondering if I should drain half the coolant out and replace it with straight water and pink water wetter. It claims to knock down temps about 10 degrees.



Could it be a bad thermostat? Or what if there's air in the system?

Red Raspberry

May be air but if there is then there is either a leak or the cap is bad. A new cap would be cheap and easy. If you get a higher than OEM pressure it will help too.



If the cap is bad and no pressure is allowed to build up them micro boiling will happen and raise the temps pretty dramatically. It may also not allow the coolant to be drawn back into the system when the engine cools down after shutting off. This is where the air comes from.



I've never had any luck running straight water and water wetter. I know they say it's the best for cooling but just my experience.

pas1216

The A/C is shutting down on high pressure when the temp get too hot.

onecrazyfoo4u

Okay I'll probably try a new cap and thermostat just since they're cheap. As well as more water than coolant (not much risk of freezing in the desert). I definitely don't have a leak. I've checked several times and its all squeeky clean.



Is 230 degrees too hot to be running at regularly? 150 intake temps seemed pretty darn hot too.

Red Raspberry

I would say it is. Can you measure oil temp? It will be hotter than the coolant.



The T stat only sets minimum temp. What does it run if you just let it idle and warm up? You can see the t-stat cycle when it reaches the opening temp.

pas1216

You can always run no tstat and wire the fan to come on when the engine starts and have it run constant. There has to be a reason for the car to be running that hot.

onecrazyfoo4u

I can't check oil temps. In fall, winter, spring the car ran at 180-190 degrees all the time. This is my first summer owning the car so I'm just trying to figure out if there's an issue. Sounds like it is running too hot though. I'll have to check what temp it runs at just idling on a hot day.



If I get a higher pressure radiator cap, will it cause any blown hoses or anything? I thought it might help to get a lower temp thermostat to open it up sooner. What is the stock thermostat opening temperature?

Stocker

If it's 100+ outside, blacktop will easily be 120-130+, plus another 20 for the engine's radiated heat and the hotass air from the radiator isn't cooling anything either. 150 is hot, but doesn't sound impossible to me. Yours isn't the only thread out there with somebody astonished by 150 degree IAT readings. Sometimes, it just gets that hot.



http://www.mazda-speed.com/forum2/in...?topic=23501.0