Hurricane coolant leaks possibly not modeled correctly.

[FeuerFliegen]

I was playing a single player mission today, in a VVS Hurricane.  I got shot by a 109 and sustained a coolant leak.  I didn't realize it at first; I thought it was a fuel leak, as I would have gone straight back to base had I known.  After 20-25 minutes of flying around and noticing that my fuel gauge had only gone down a normal amount from flight time, I examined the leak closer and saw that it was the bright white coolant leak that is a different color from a fuel leak.  I then had to fly 90km back home to base, including climbing from 500m up to about 4000m.  Not once did my engine run hot; nothing like when I get a coolant leak in any other plane.  After I landed, I 100% confirmed that it was a coolant leak, as it was steaming out of the radiator, opposed to a liquid pouring out onto the ground like a fuel leak would.

 

So I'm pretty sure that there was a bug that was not actually removing any coolant from the system.  Any other plane would have overheated pretty quickly after a few minutes of leaking.

 

I recorded a clip for a minute or so after I realized this, if you need a .trk file.

 

I was not using any simplifications in the game, such as unbreakable, invulnerability, etc.

[LukeFF]

Yes, we absolutely need the track file and associated mission for the team to look into this.

[the_emperor]

Yak-9 can don the same trick

[FeuerFliegen]

17 hours ago, LukeFF said:

Yes, we absolutely need the track file and associated mission for the team to look into this.

 

Here it is.

11.2025-06-30_02-34-30_00.rar

[FeuerFliegen]

@LukeFF

 

The same exact thing happened to me in a Spitfire Mk.IXc

 

It was even on the Normandy map; very hot outside air temperatures.

 

Here's the track for that one.

11.2025-06-30_02-34-30_00.rar

[FeuerFliegen]

Ugh...  I'm 98% sure it's the same issue with the Mosquito.  I just flew over 180km with a coolant leak.  I didn't fully realize it until I landed because there were several fuel leaks, but once I landed I could see the hot steam evaporating at the engine.  I thought I saw the coolant leak when I first received damage, but after traveling for over 100km, I was able to rule that out (or so I thought) because my engine temps hadn't changed, and both engines were equal in temperature (only one engine received the coolant leak).

In my opinion, this is a really bad issue... talk about an unfair fight.  And it also makes me wonder just how many planes this affects.

Edited September 20 by FeuerFliegen

[Bilbo_Baggins]

10 hours ago, FeuerFliegen said:

Ugh...  I'm 98% sure it's the same issue with the Mosquito.  I just flew over 180km with a coolant leak.  I didn't fully realize it until I landed because there were several fuel leaks, but once I landed I could see the hot steam evaporating at the engine.  I thought I saw the coolant leak when I first received damage, but after traveling for over 100km, I was able to rule that out (or so I thought) because my engine temps hadn't changed, and both engines were equal in temperature (only one engine received the coolant leak).

In my opinion, this is a really bad issue... talk about an unfair fight.  And it also makes me wonder just how many planes this affects.

 

I've noticed this a good while ago with many of the machines all doing the same. Brought it up here and sure enough, nothing was done.

 

Very in disappointing and obvious issue.  Blown water coolers don't do anything. 

[FeuerFliegen]

1 hour ago, Bilbo_Baggins said:

 

I've noticed this a good while ago with many of the machines all doing the same. Brought it up here and sure enough, nothing was done.

 

Very in disappointing and obvious issue.  Blown water coolers don't do anything. 

 

It's even worse that some planes do, giving a very unfair advantage.  If I shoot a 109 and it gets a coolant leak, all I have to do is keep him busy for a few minutes and it's over.

[FeuerFliegen]

Just happened AGAIN for the Yak-7B.  I'm starting to think it's only a small minority of planes that even have coolant damage/leaks modeled properly.

 

I have another .trk if you need it, but I think it should be pretty easy to research at this point.

[Bilbo_Baggins]

15 hours ago, FeuerFliegen said:

Just happened AGAIN for the Yak-7B.  I'm starting to think it's only a small minority of planes that even have coolant damage/leaks modeled properly.

 

I have another .trk if you need it, but I think it should be pretty easy to research at this point.

 

Yeah they always harp on insisting for the tracks but it's so bleeding obvious it's not funny. It's a glaring and fundamental error; wish they'd just fix and be done with it. 

[LukeFF]

Guys, this is how the QA process works with our team. Between all the work being done on multiple projects, there isn't the time to chase down all these reports of one thing or another not working if there isn't a track file provided. Not only that, these files allow the team to pinpoint exactly where there might or might not be a problem. 

[Aapje]

1 hour ago, Bilbo_Baggins said:

 

Yeah they always harp on insisting for the tracks but it's so bleeding obvious it's not funny. It's a glaring and fundamental error; wish they'd just fix and be done with it. 

 

In reality people are often extremely bad at accurately describing the issue, and the issue can also be with stuff happening elsewhere in the mission, that the player is not even aware off. And people report issues as bugs that are not bugs. Etc.

 

They are not asking for no reason, but because it makes it much more likely that they can quickly and effectively investigate the issue.

[ST_Catchov]

No need for tracks. Let's not waste the dev's time. It's simply superior British and Soviet engineering. 

[MDzmitry]

If anyone here can set up custom missions, try making one with a bunch of fighters of different types, fly something with nose-mounted 7,62 (Yak-1/Bf 109 F) or 12,7mm (Yak-1B, Yak-9) and target radiators specifically.

Start recording a track and make a bunch of water leaks in each target. After that keep flying and checking what aircraft flies for how long. 

[the_emperor]

https://limewire.com/d/ytF53#XVI0gh9yUC

 

Yak-9 runs 30min with hit to the radiator

 

example of a Yak 9 running with a leaking radiator till I run out of fuel already posted here (but was ignored thus far)

additionally the Yak-9 Airframe seem very sturdy and the radiator even sturdier as it is very hard to damage

Edited October 19 by the_emperor

[FeuerFliegen]

On 10/17/2025 at 7:01 PM, LukeFF said:

Guys, this is how the QA process works with our team. Between all the work being done on multiple projects, there isn't the time to chase down all these reports of one thing or another not working if there isn't a track file provided. Not only that, these files allow the team to pinpoint exactly where there might or might not be a problem. 

 

 

Both .trk files that I posted in this thread, back in June/July 2025, both say "0 downloads"

 

 

That being said, here's another one... for the Yak-7b.

Yak-7bcoolantleak.rar

[the_emperor]

Yak-9 48min flight with a leaking radiator...eventually ran out of fuel 😂

 

https://limewire.com/d/HXYeq#tQ3SNS3qBp

[Bilbo_Baggins]

14 hours ago, the_emperor said:

Yak-9 48min flight with a leaking radiator...eventually ran out of fuel 😂

 

https://limewire.com/d/HXYeq#tQ3SNS3qBp

 

21 hours ago, FeuerFliegen said:

 

 

Both .trk files that I posted in this thread, back in June/July 2025, both say "0 downloads"

 

 

That being said, here's another one... for the Yak-7b.

Yak-7bcoolantleak.rar 2.1 MB · 2 downloads

 

brilliant guys. If this isn't enough, then only God knows what more is needed. 

[FeuerFliegen]

I also had a Spitfire Mk.XIV last 40 minutes with a coolant leak, which I thought was very unrealistic, but I've started with only mentioning planes that can appear to literally go forever on a coolant leak.

[the_emperor]

Spitfire IX 40min radiator leak

https://limewire.com/d/OfmZs#CPe8RJ5zw7

[Bilbo_Baggins]

13 hours ago, the_emperor said:

Spitfire IX 40min radiator leak

https://limewire.com/d/OfmZs#CPe8RJ5zw7

Brilliant.

 

Where do we post this stuff so the devs actually fix it? I can already imagine 'track required to be submitted with the correct documentation and appropriate procedure with historical evidence attached'. Or do we just keep whining here? 

 

Same thing with AI in ME262 and Ju88 C6 model performing level bombing without bombsights. I reported both this and the watercooler inaccuracy a while ago but it just doesn't get fixed. 

[FeuerFliegen]

43 minutes ago, Bilbo_Baggins said:

Brilliant.

 

Where do we post this stuff so the devs actually fix it? I can already imagine 'track required to be submitted with the correct documentation and appropriate procedure with historical evidence attached'. Or do we just keep whining here? 

 

Same thing with AI in ME262 and Ju88 C6 model performing level bombing without bombsights. I reported both this and the watercooler inaccuracy a while ago but it just doesn't get fixed. 

 

 

At this point I think the problem plagues so many planes that it would be more work than anyone is willing to do.

[FeuerFliegen]

Wow... playing around with different planes, I took a P-38 and went to manual water radiator mode and closed them both to 0%.  the temperature went to 140 degrees, and I never got an overheat warning, no coolant evaporating coming from the engine area, just flying like normal with no issues.... I was finally able to get it to give an overheat warning at about 150 degrees by putting it in auto lean mixture, but then I just let the plane fly with closed water rads and nothing ever happened, even with the temp gauge maxed out...  so if you want to squeeze more speed out of your P-38, just close the water rads! 

 

 

The oil rads do seem to work properly though; if the oil overheats, the engine(s) will die.

 

And this was a summer map too.

[the_emperor]

https://limewire.com/d/gejns#McCKpf9HtD

P-51D 30min radioator leak...

 

Edited October 24 by the_emperor

[the_emperor]

https://limewire.com/d/Ewaed#Ndmbna5KFe

50min Hurricane Radiator Leak

[the_emperor]

Here are more examples

1. Spit IX 40min Radiator Leak

2.Yak-9 ~50min Radiator Leak flight on full Power!!!!! till I ran out of fuel...So I guess this issue is now top priority to getting fixed?

 

 

https://limewire.com/d/wVlgA#JzTtvUT3hZ

[the_emperor]

https://limewire.com/d/EexCE#Cv2FDwS2I5

and another infinite Yak-9 rad leak until fuel is gone

 

 

https://www.youtube.com/watch?v=ldS5mN0QjWo&t=297s

 

only exception is the 109 which has a radiator cut off and can keep flying on one radiator. 

Edited October 24 by the_emperor

[the_emperor]

https://limewire.com/d/vXYrp#NjVLkd8mbh

 

20min Radiator Leak P-51 & G-6

[the_emperor]

I would like to add, that  overheating for the Yak-9 starts at ~112C instead of 100C based on the manual you base your engine models on.

[Gavrick]

I'll check what might have broken in the radiator leak. I think we'll fix it by the next patch.

[the_emperor]

@Gavrick

many thanks for still fixing and improving the game.

Any chance the later 109 series gets the radiator cut off as its a crucial and very unique part of that aircraft?

[Bilbo_Baggins]

8 hours ago, the_emperor said:

@Gavrick

many thanks for still fixing and improving the game.

Any chance the later 109 series gets the radiator cut off as its a crucial and very unique part of that aircraft?

 

And thanks lads for the work with getting all the tracks and tests done. This one has been bugging me for ages.

Edited October 28 by Bilbo_Baggins

[Aleksander55]

If it's not too late for this information: AI 109s also fly forever with both radiators damaged and leaking. As in fly at high power for up to 5+ minutes, climbing etc, then after they finally start to lose  power they'll fly 50+kms back to their base.

 

Let me repeat, I always puncture BOTH radiators of any 109 I fight. So, no excuses of cutting off one of them.

 

No tracks as the sim is not updating and working on my system right now.

[FeuerFliegen]

On 11/3/2025 at 7:02 PM, Aleksander55 said:

If it's not too late for this information: AI 109s also fly forever with both radiators damaged and leaking. As in fly at high power for up to 5+ minutes, climbing etc, then after they finally start to lose  power they'll fly 50+kms back to their base.

 

Let me repeat, I always puncture BOTH radiators of any 109 I fight. So, no excuses of cutting off one of them.

 

No tracks as the sim is not updating and working on my system right now.

 

I hadn't had that problem... in fact, the Bf109 is the one plane that I know it works in; in real life it might be a little quicker, but there have been a few times in single player that I put a water radiator leak in a 109, I follow it around, and eventually I'll see the radiators open 100% and the engine dies a minute later.

[the_emperor]

Did a couple of tests with the 109...

1 damaged radiator lets me fly about 20min

2 damaged radiators lets me fly about 5min.

( .30 cal damage like in the tests before)

at least with two radiators the time seems closer to reality.

[[CPT]Crunch]

109 has isolation valves in the cockpit for each wing radiator.  So it should still have half its cooling capability still working once one side is shut by the pilot.  Sounds like it's working and we already know in this sim the pilot performs many functions automatically like switching fuel feed valves.

 

Shouldn't be no reason a 109 pilot can't make it home by throttling back and watching the temps with only one side out.

[357th_KW]

The issue there still being that the pilot is instantly and correctly identifying the leak and isolating the correct radiator, while in the middle of a dogfight.  And then continuing to dogfight for many minutes with 50% cooling capacity.

 

Bear in mind that real world pilots often struggle to immediately identify which of their two engines failed under the stress of the emergency, which is much more obvious.

 

The historical scenario you often read about is where pilots would take a radiator hit over England and in many cases not even make it back to the channel, let alone all the way to France.  In game it turns it into a situation where pilots can comfortably finish their dogfight and then cruise back across at low power without much stress (and again, this is true for pretty much all liquid cooled fighters in game).

 

If you take a stray flak hit to the radiator and are able to limp a short distance home with the power pulled back, that seems at least somewhat believable.  But the continued dogfighting with degraded cooling, and then still returning to base is the part that seems completely far fetched.

[MDzmitry]

56 минут назад, 357th_KW сказал:

The historical scenario you often read about is where pilots would take a radiator hit over England and in many cases not even make it back to the channel, let alone all the way to France.

For a bit of context, radiator cut off appeared starting only with Friedrich. Emils still had none of that.

 

A bit of going off on a tangent about radiator cut off, viewer discretion is advised

Скрытый текст

On the other note, I think it's worth pointing out that cutting off a radiator doesn't magically make it stop leaking "and that's it". As you rightly mentioned, an aircraft loses 50% of its water cooling surface in exchange for not losing the coolant. And such a decrease is a lot, really. Fair for trying to struggle back home, flawed when compared to what the game's showing. 

 

If one wants to suggest a mechanic similar to radiator cut off, the easiest option would be to give each underwing radiator a specific volume of coolant it loses before the pilot "notices and acts", stopping the leak and rendering the radiator inefficient. In easier terms: "make the leak timer independent and severely less before the radiator ceases functioning as such".

But that would basically result in a scenario that if both are hit, then both would get blocked early, leaving us theoretically with some coolant saved, but none of it being used. So not any better than just losing all the coolant from leaks. A counter could be to make the aforementioned system only work for the first radiator hit, leaving the other one with the old "leak till there's nothing left" approach, but that would be even more of a bother to implement.

 

But well, no more going off the main topic of bugged leaks. The timers are still absurdly long, so there's that.

For now let's just wait and see if the issue is addressed in the next update.

[FeuerFliegen]

On 11/7/2025 at 10:04 AM, 357th_KW said:

The issue there still being that the pilot is instantly and correctly identifying the leak and isolating the correct radiator, while in the middle of a dogfight.  And then continuing to dogfight for many minutes with 50% cooling capacity.

 

Bear in mind that real world pilots often struggle to immediately identify which of their two engines failed under the stress of the emergency, which is much more obvious.

 

Cliffs of Dover does this well; I have been in a Bf109F, received a water radiator leak, and it was hard at first for me to analyze which side it was coming from.  One time I shut off the wrong side (the good one) as it was pretty difficult for me to tell which one was leaking.  And even then, being that you only have half of your cooling system, you still need to go straight home and keep your engine at a low power setting.

 

That being said, I don't think this aspect is modeled in Great Battles in any way, regardless if it's AI flying or not.