This comes down to basic liquid cooled late model auto tech. The heat generated by an engine is always present, and depends upon load, coolant quality, how clean your Radiator and engine are, and outside ambient air temp and humidity. When you take out your TStat, or choose a lower temp TStat you are shifting heat from the engine into the radiator. It did not go away, your engine still makes the same heat, you just packed some of it it in the coolant hoses and radiator. Which short term may seem like a good idea, until the source of cooling (the Radiator) is heat soaked beyond its capacity to cool any longer and slowly builds to a hotter than expected coolant temp. Somewhere in there the PCM will start its control by taking advance out of spark tables, reduce fuel = power to in turn reduce heat because its factory tune is set to run in conjunction with a 195F TStat in place. Many of our customers in the Deep humid S and hot SW have reached out explaining they feel reduced performance in summer extremes and wonder why. That is because cooling is controlled in modern vehicles not just mechanically (TStat), but electronically by your PCM tune. Power makes heat. Reduced power = reduced heat.

Back in the day, I ran some wicked Street Strip Oldsmobiles. There would be "those guys" that would boast they removed the TStat to "cool the engine". In the morning (when the track surface and air were cooler) it would seem like they made a good bet. As elimination rounds continue into mid afternoon when there was a hot baked track, heat/humidity of the day as well as less time between runs, I could spank all there silly azzes with my TStat right where it was supposed to be because they could not burn all the fuel they were cramming in the cylinders and their mechanical timing was off. Livin' and learnin'. I digressed........

The goal is to always keep the Radiator temp lower than coolant in the engine block so.............. it can cool when it is needed.

Back to the H3. One of the common problems I have seen with high heat and H3s is dirty radiators, like from mud and cruddy water dried in. Not to mention bugs, leaves, and crud that accumulates in between the AC Condenser and the Radiator. I would be looking there before messing with any TStat. Last time I had my Radiator out for the Cam swap I vacuumed the back side of the Condenser and front of the Radiator with a shop vac bristle attachment. More crud in there than I would have thought.

I am done here, you guys are all hot and bothered about............ cooling.

 

Lolz. 🤣

Beats getting all steamed up about it. 😆

 

My operating temp stays within the NORMAL(195°-210°) range, my A/C blows cold (30°+ under ambient temp), & my beer is around 35° every time I open 1.

 

Thanks for all the info, makes sense about engine running at lower performance to reduce heat. What are your thoughts about placing a t-stat St the upper hose rather than were it is now? On the I5 of course.

 

Nothing wrong with a custom mod given you extreme summer heat. A couple people here did that. Somebody mounted it in an in-line upper hose cylinder that could be easily accessed to swap out the TStat when the seasons changed. That was a while back and I do not remember who or exactly why.

Make sure your Condenser and Radiator are clean as well.

How 'bout those Golden Knights! Impressive for sure.

Good luck.

 

Nonibot Any update?

 

Car seems to run cooler while in motion 200-217F, however while idling I am getting 230f while transmission coolant temp stays at 210f. Once I start moving temps come back down to 217f. What do you think? I will give the radiator a hose down once the vehicle cools down a bit. I did replace the fan clutch with an o'reilly one, but looks like the previous fan clutch was also an o'reilly one. So I am wondering if their clutch is just garbage.

Golden Knights is all the rave right now, people love em here. When we first moved to the state we were confused with all the Knight car plates. This is what our plates look like around here.

 

Temp too high! Use a garden hose with high pressure spray nozzle to wash away ALL debris(outside-between-inside) no matter what the coolant temp is at.

 

As I am cleaning the radiator, I think I am missing the lower radiator baffle deflector. Would this make any difference?

 

A baffle changes the course of airflow or re-directs it to another location to keep heated parts cooler.