Engine Temperature on hot days

[Klunk]

Normally my I20N engine temperature is around 100°C, but the other day the outside temperature was 38°C and the engine temperature sat on 85-86°C for an extended drive, the next day at 35°C outside temperature, the engine temperature was at 100°C again.

Does anyone know the reason for this?

 

[i_twenty_N]

That's the coolant temperature, more revs, the faster the waterpump spins. More speed more airflow for the cooler, also the thermostat is regulating.

 

[Klunk]

Yes I understand it is the coolant temperature, but it is normally controlled at around 100°C, but on a hot day (i.e. 38°C it was controlled at around 85°C, this is repeatable and only when the outside air temperature is very high. I thought that maybe this has been designed to control the block temperature as less heat is expelled directly by the surface of the block. The oil temperature was also in the 80s. To me it looks like a programmed design feature, as it is so different from the normal coolant temperature and so constant .Or it could be to offset some of the performance impact of warmer intake air.

 

[i_twenty_N]

Hmm, maybe the thermostat is electronically controlled via IAT sensor, and it opens more. Additionally could be immense ignition retard.

 

[Klunk]

The engine performance didn't feel any different to normal, so I don't think ingnition timing was changed. I expect the coolant temperature is controlled by the ECU and this is by design. I just wondered if anyone else had noticed this or knew the reason. I know that if driven very hard the boost pressure is managed to control the coolant temperature, but this is only when the coolant is around 120° as I understand.

Perhaps it is done so the raditor doesn't heat up the intercooler too much, to control the charge air temperature?

The car was delivered September 23 and has all current updates afaik.

 

[Zealot]

Ok, this seems to be a normal function in extremely hot weather.

Yesterday, where I am in South-east Queensland, the outside temperature was 38-40. My car, which had always run at ~99c, was heating up to that and then suddenly rapidly dropping to exactly 86c. If I stopped and restarted it would go through the same cycle.

I was concerned about it at first, but then I thought maybe it's something Hyundai have done to help protect at least this particular vehicle in extremely hot weather. It just seemed too consistent and coincidental with the hot ambient temps. If so, there must be some means to allow increased coolant flow under those conditions.

Today the temp is 30-32c and lo, and behold, the car is back to running at 99-100c under normal driving conditions, so it would appear this is indeed what is happening. Finding this thread where someone experienced identical behaviour under exactly the same conditions also makes it seem to be by design.

I did consult the manual but I couldn't find any mention of running temps being lower during extreme heat. I may have missed something but you'd think Hyundai would put it in there. Maybe I'll try and get an answer from them.

 

[takeru-hayabusa]

This post is a bit older, but I can also provide some feedback on this.

Normally, based on my daily driving habits, my engine temperature is around 100–102 degrees. In the summer—though only on some days—I’ve also noticed that the temperature (of the oil and engine) is lower than usual.

Yesterday, it was 37–38 degrees in Germany. Even though I was driving at a brisk pace, my engine temperature was 86–87 degrees. This morning, at about 20 degrees, everything was back to normal (about 101 degrees).

Since this low reading is so rare—even though I vaguely recall having experienced something like this 2–3 times in recent years—I went straight to the forum and searched for similar reports.

So, I can confirm that at very high temperatures, the engine cooling behaves differently and the temperature is lower than one would expect.