It does not matter how long you've been playing IL2
I've been flying for more than 10 years and it's not a little, will not you agree?
But this does not apply to our question.
In the last patches appeared the problem, about which I wrote earlier.
At all BF 109 (without MW50) flaps in auto mode work correctly, and on BF 109 with MW50 – not correct.

P.S. Regarding the temperature indicators in BF 109 K4:
Upper - Temperaturanzeiger für Kuhlstoff - water temperature
Under - Temperaturanzeiger für Schmierstoff - Oil temperature
Learn the manual Kameraden)))
http://www.airwar.ru/other/bibl/bf109k-4.html

Gentlemen,

I flew little in Bf 109s and they were mostly 109E and 109Z (yes, I'm pervert). So my knowledge of this family is limited.
But I'm not sure about the claim of irrelevance (or "coming too soon") of "engine overheat" message for ALL airplanes.
As I remember, it was not so important in earlier versions of the game but then the engine management was reworked somewhere between 4.07 and 4.10. Unless I'm wrong?
One of my favourite pastime today is hunting AI heavies in multiplay. (Or human piloted heavies - but they are so rare). When I do that in my trusted Bf 110 I have to remind myself to set radiators to full open before any attack. If that is not done and I don't react to warning message promptly - then engine(s) damage is inevitable. Of course, it happens just before I make my best shot ever or when I need to escape from gunners crossfire. Murphy's Law is part of the IL-2 code, I believe. :cool:

Sorry for going slightly off-topic. Just a humble opinion of the modest twin engine fighter pilot. Who prefers HUD messages to gauges because the latter are harder to read for weary eyes of the seasoned twin engine fighter pilot...
;)

If you don't like the how auto setting behaves, then why not just override it by manually opening the radiators all the way? That's why there are manual settings as well.

I just indicated the problem. maybe the developers will fix it.

I am assuming you guys are talking about 4.13.4 version. If not, then disregard any of this post.

From the Aircraft Guide, located in you game folder:
BF-109K
Gauge 14 --- Coolant Temp (Top right)
Gauge 15 -- Oil Temperature (Directly below Gauge 14)
(I hate to say it treetop, but you got this wrong)
BF-109K C3 ---- Gauges are in the same place.

Now lets look at the Temp Guide, also in the game folder:
For the Bf-109K, its given as 115/80. 115 is coolant limit (gauge 14), 80 is oil limit (gauge 15)

Now I haven't flown the 109 much. I do agree if the engine is overheating, the cooling flaps should open fully. Because I haven't flown this plane, I cant tell if that happens or not. And just a question, there isn't a radiator indicator in the 109, so how are you sure its only opening part way and no fully?

Just some advice, from the same guide:
General flying tips:
Watch your temperatures all the time, avoid using excessive power settings for longer
periods of time. Only stretch your engine when it needs be - at take off, during actual combat.
Use maximum permissible climb settings to get to your desired altitude and cool your engine
down while cruising. The more headroom you’ll have before combat the better - that means that
you can fly at full power longer if you need to. Fly fast - the speed of the outside air is helping
you to cool down your cylinders or coolant. Fly high - the temperature of the outside air is
helping you to cool down your engine, too. Don’t underestimate your environment - hot maps
make it harder for you to keep your engine cool, as hotter air is cooling your engine. Watch your
temperatures at all times and for general advice, please refer to following chapter of this
document for temperatures set on various maps in the sim.


Hope this helps, and like I said, if not using 4.13.4, none of this info is valid.

You can see the radiator flaps in external view, or in-cockpit if you lean to one side. They don't always open fully when the "Engine:Overheating" warning is on.

However, as has already been said, the warning can come on too soon. You can fly indefinitely with the overheat warning on and the gauges only reading 105°/75°. The cooling flaps might not be fully open at that point but will open further if they need to. If there is a problem it appears to be with the warning not the flap operation.

I think the overheat warning should at most be taken as a reminder to keep checking your gauges.

Check the full rad open isn't confused with landing flap position.

Are thy both the same or only available full rad open position in landing flap position ?

:confused:

Maybe!

You are welcome! Make the radiator open correctly.
Now, unfortunately, the radiator on the BF-109 K4 opens from the oil temperature. But it should open from the temperature of the water !!!