I’ve been trying to find out exactly what the car normally runs at and when it overheats in Fahrenheit. mind you I use a scanner to get my temps since my gauge has a mind of its own. I’m looking for temp in F not the usually 3rd bar or In-between, my car runs at 190 F to 199 F in my towns 90 to 100 F ambient temp I’m wondering if maybe the ambient heat is putting stress on the car or if I’m overheating.
also it’s a 1999 ls400 running proper mixed coolant. Water pump and timing belt replaced at 205k now at 239k. coolant flush, t-stat, rad cap and ect done at 239k. I’m looking for normal operating range in Fahrenheit and where you should be worried in Fahrenheit.

 

Thermostat is rated at 82-95 degrees C. which puts your coolant temp exactly in specification. 'Stat starts to open at 82 starts and is closing at 95.

 

is hitting 220 F or 104C bad, during a heat wave of 115 ambient temp I was running my ac and the car got up to 220F or 104C before I realized and I threw the defrosters on max to cool it back down.

 

I think 115 ambient is about the limit of the cooling system. Defrost doesn't cool the engine down that's not how the system works.

 

220f is fine if you start creeping to 230 then turn off the AC.

 

can you notice the coolant gauge ever actually moving? as long as it's sitting just above that 2nd tick mark you're totally fine (which is about 200°F)



also yea the defroster won't cool the engine (the opposite actually since it uses the A/C), for that you'd need to turn on the heat