That’s hot

I’ve never figured that out. It’s hard enough to find written info on what is too hot for any engine.
The most common recommendation is you want to keep it under ~235F. People have said they got it there on a hot day at highway speed uphill with A/C on. Or slow speed desert crawling. But when they turned off A/C, turned on the heater and rolled down the windows it dropped by ~20F.

What is often stated is the coolant diluted 50/50 has a boiling point of 228F at atmospheric pressure and 248F at 15 PSIG. So you don’t want the coolant to boil.
But I’ve never seen any auto experts state what actual temperature starts causing damage to their engines.

 

You didn't need her anyway! She was a chronic complainer looking for a place to happen. Stay hydrated, and go pickup the 2 new customers down the road from "the crab"!

 

I hadn't thought about using these. I have portable Ryobi fans I run in the car and turn the AC down while I'm away from the car. Trying not to strain the cooling system too much. The OBDII plug-ins I've used in the past only connect via Bluetooth. Which only gives me about 30ft of connectivity.

 

Probably had an aerosol can that exploded from the heat and caught on fire. That happened a couple times in Iraq and Africa when I was there.

 

Something blew up ignited the fire, not the car, otherwise here in Phoenix we wouldn't have any vehicles to drive.

 

You shouldn’t have to monitor your radiator temperature constantly from a distance. You can run the OBDII interface and phone app and characterize your cooling system at various outdoor temperatures and loads. In your case it seems you’re just concerned about idling in Park on a hot day with windows mostly closed.

I’ve noticed with my 18 ORP, basically stock, on an 80 degree day with A/C on driving in stop and go traffic, or even at 65-75 MPH, or when idling, the coolant temp stays right around 187F. Outdoor temp of 70F the coolant reads 185F. The 4R cooling system works very well when properly maintained and if your radiator fins aren’t full of bugs or mud.
Heavy trailer loads and high ambient temps are another matter.

The way I drive even in the worst conditions I don’t think I’ve ever cracked 205F. As @LandCruiser was saying about the temps of older vs newer engines, it seem the 1G 4Runner engine runs like an old cool one.

 

I'm wondering if this was caused by a leak in the A/C system. I can't tell what year the truck is in the pic but the new refrigerant they use is somewhat flammable. I'm not sure what year they switched over from 134A to R-1234YF but my 2021 4Runner and 2021 Acura RDX has it. Does anyone here have experience with this new refrigerant?