Engine dies after takeoff

[lothar29]

It just uploaded, so it may take about 5-10 minutes to be in HD.

hace 28 minutos, Art-J dijo:

What about the usual culprit number 2: MW-fuel selector switch? Have you checked if it's in correct position when you spawn?

the MW-50 is in the off position

[razo+r]

55 minutes ago, lothar29 said:

It just uploaded, so it may take about 5-10 minutes to be in HD.

the MW-50 is in the off position

That's not what perfectly warming up the engine looks like.

You rev it up quite high for a cold engine, exceeding the maximum oil pressure. At takeoff, your engine is barely at minimum temps, and you exceed the maximum oil pressure yet again.

You should try applying throttle a bit more carefull while paying attention to the oil pressure and temperature gauge. When the oil pressure spikes above the maximum value, it's indicating that the oil is still too thick/not warm enough, and you should wait until it's ready.

Additionally, I see you got the MW/Fuel switch on the wall in the fuel position and enable the MW switch on the dashboard, followed by a shaking of the engine when you briefly go full throttle. That might also contribute to your engine tearing itself appart.

Edited October 2 by razo+r

[peachmonkey]

2 hours ago, lothar29 said:

the MW-50 is in the off position

he's talking about the mw-50 vs fuel in the mw-50 tank. Technically, you overboosted the engine only once (without mw50), so this switch's position shouldn't really matter that much so early into the flight time, however I noticed you got to 2600rpm & 1.4 ATA pretty quickly and stayed there until the engine failure. Try limiting to 1.3 ATA max and see if that extends the engine's life (don't over-boost to 1.8 ata either, even if just for a split second).

null

Edited October 2 by peachmonkey

[lothar29]

What has me completely baffled is that from the moment the BF109K-4 came out in access, I have never had these problems with engine stops. I don't usually fly it live, but I have flown it a couple or three times a week, and this has been a surprise to me.

[peachmonkey]

14 minutes ago, lothar29 said:

What has me completely baffled is that from the moment the BF109K-4 came out in access, I have never had these problems with engine stops. I don't usually fly it live, but I have flown it a couple or three times a week, and this has been a surprise to me.

there has been an 'engine cooling' update about a year ago, or more, not sure if you haven't flown for that long. For the most part if you stay within the advertised engine regimes there's not a lot of 'bugs' that pop-up. However, if you start firewalling the throttle (even for very short periods of time) the answers to the questions such as "why did this fail?" become pretty elusive. That's DCS for you.  

[Art-J]

@lothar29 Putting all cooling related aspects aside, as peachmonkey noted above, in the video your MW/fuel selector is set to "fuel" instead of MW mixture. If your plane was in standard config (ie. aft tank filled with MW mix), that means you were constantly dumping water and methanol into your fuel system. Petrol engines don't run on water , so your DB605 quit after a while.

It's been modelled like that since module release by the way and default selector position has always been "MW", so If yours is flipped down after spawn, I would check if something hasn't changed in your control bindings after the last update. 

[peachmonkey]

1 hour ago, Art-J said:

 MW/fuel selector is set to "fuel" instead of MW mixture. If your plane was in standard config (ie. aft tank filled with MW mix), that means you were constantly dumping water and methanol into your fuel system. 

I was suspecting this, but is it really feeding fuel to the engine continuously if one doesn't push the throttle to the max 1.8ATA/max RPM?  I thought it'd do it only in the max position?

[Art-J]

Years ago I was wondering about the same at first, but later when I thought about it - if aft tank is supposed to provide extra long range fuel supply in that configuration for all flight including cruise, it wouldn't make any sense if it worked only at emergency power, would it?

I didn't investigate the ins and outs of the system deeper, though, 'cause I usually don't use aft tank for fuel anyway.

[lothar29]

Thanks everyone for your comments, but I'm preparing another video with everything in working order, and soon the same thing happens.
I need to figure out if it's my fault...

Thanks

When the video is ready, I'll upload it and see if you can give me ideas about what mistakes I'm making.

 

Edited October 4 by lothar29

[zerO_crash]

On 10/2/2025 at 9:46 AM, lothar29 said:

I let the engine warm up perfectly, neither at maximum nor at minimum. In my opinion, it's the oil pressure that renders the engine useless.

I always activate the automatic prop pitch; it's mandatory for perfect coordination on DB6xx engines. We all know that without the automatic propeller system, it would be impossible to keep the engine in its perfect operating range without breaking the reduction gear or the propeller planetary gear system.

I'll send you a video now.

 

Thanks for answering

 

Don't assume that just because you can't, nobody else can. I have flown the BF-109K4 with manual prop. pitch in combat without any issue. Actually, it is more work to keep it properly alinged manually so as to not over-rev or over-torque the engine, but you can push more out of the plane versus automatic governor. The automatic governor is not perfect, far off. It is there, to automate a part of the flying, such that he pilot can dedicate more of his attention to the actual combat. 

 

Frankly, it had to do with Germany losing pilots faster than it was able to replace them. This is an example of a measure meant to alleviate that problem, by shortening the curriculum for aspiring Luftwaffe pilots.  

 

Send the video over, and I'll let you know what you're doing wrong/what's happening.

Edited October 4 by zerO_crash

[zerO_crash]

On 10/2/2025 at 2:05 PM, lothar29 said:

It just uploaded, so it may take about 5-10 minutes to be in HD.

the MW-50 is in the off position

 

Ok, let's see where the issue stems from (extract from the manual):

 

 

Let's start with LITERALLY the first sentence of this chapter! Read it? Good! Now have a look at your tachometer - 1200RPM right off the bat!

 

Go through the actual procedure, read the manual, and you won't have problems. (I know for a fact, that the engine seizing to work later in the flight is most often the culprit of having improperly warmed up the engine. You ain't the first, and neither the last to experience this.)

 

Another quick note; you don't need to murder the primer pump to start a Daimler. Three strokes are more than enough during what you might call average weather conditions. In winter, you might want to do 4-5 injections are plentiful. How will you know if you primed it enough? Simple, when you pull the starter handle, watch the fuel pressure gauge - 0.8 bar during engine start-up is perfect. Anything below, let go off the starter handle, and stroke it some more. (The manual does state that you might need as many as 15 strokes, but that would have to be a very hard beaten Daimler, stored for years with neglect. You won't need that many.)

 

Yet another note: you move the throttle forward during start-up, which is not needed at all in the BF-109K4. Actually, in order to specifically not go above 600RPM, you should barely nudge it, as in, barely. That will also solve your uncontrolled rolls during start-up.

Edited October 5 by zerO_crash

[Art-J]

^ All fine and dandy, but irrelevant in this case, as the one and only reason why the enigine quit in second video is the same as in the first one - MW/fuel selector on left side of the cockpit is down (fuel) position while it should be up (MW mix). By the way, manual doesn't say to check it, so even if he follows the manual to the letter, his engine will still keep quitting.

The plane should spawn with selector up, so it's probably a controller binding issue.

 

Edited October 5 by Art-J

[lothar29]

Thank you very much, I'll try again.

PS: So, the tutorial on how to start the simulator is wrong. It's limited to the most basic.

[zerO_crash]

On 10/5/2025 at 4:08 PM, Art-J said:

All fine and dandy, but irrelevant in this case, as the one and only reason why the enigine quit in second video is the same as in the first one - MW/fuel selector on left side of the cockpit is down (fuel) position while it should be up (MW mix). By the way, manual doesn't say to check it, so even if he follows the manual to the letter, his engine will still keep quitting.

The plane should spawn with selector up, so it's probably a controller binding issue.

 

It's hard to say, as again, that engine is never heated up. Criticality- wise, I agree with you, it's a much bigger blunder. However, I've had teammates engines cease working during multi-group flights for reasons associated with proper heat-up. And while the startup list doesn't mention this specifically, the manual does state very clearly that this switch is to be controlled specifically. (Manuals pre- modern times are notorious for not being thorough, containing mistakes and generally being disorderly written. I would expect the manual to have such flaws.)

 

3 hours ago, lothar29 said:

Thank you very much, I'll try again.

PS: So, the tutorial on how to start the simulator is wrong. It's limited to the most basic.

 

The interactive training missions aren't always up to date, no. The prime way of verifying their up-to-date, is by having the newest revision of a specific manual, and controlling the tutorial against a checklist. 

 

A final tip from me: I noticed that you fly the Bf-109K4 very by the book. Meaning, if manual allows MW50 right after take-off and for 40 minutes continuous, then it'll be a 40 minute flight with maximum power. There is a delicacy aspect to flying esp. older prop aircraft. Especially back then, while the aircraft were capable, a pilot was often taught to avoid doing "stupid" things, or unnecessarily strain the machine physically. What you do isn't wrong per book, but if realism is of value to you, then you have to consider that just like you sprinting constantly would tire your body out (and shorten lifespan), so will a piston engine at maximum conditions constantly. The mentality should be that if you need it, then you'll run it up, but for a pure climb after take-off (not associated with interception - time being cruicial) or cruising, it might be clever to adhere to maximum 1.35ATA sustained. Props back then, were just a different game from jet engines of the modern times.

Edited October 6 by zerO_crash

[lothar29]

Thanks again, everyone.
Right now, I'm going to try a cold start and leave the engine at minimum rpm and wait for the oil to warm up so the pump can work without straining.

I'll record the track so you can let me know if I make any mistakes.

You're absolutely right about squeezing the engine to the maximum. No vehicle with a combustion engine can be required to deliver maximum power for a long period of time. And if we take into account that the pump pressure is at its maximum due to the cold oil, a break is inevitable.

 

Just one question... is there any way to heat the oil faster?

zer0_crash, Art-J, peachmonkey , razo+r  

Thank you for everything and your time

Edited October 7 by lothar29

[Art-J]

I recall oil cooler, unlike both coolant radiators, is auto-only and cannot be manually closed to warm up oil faster, unfortunately. 

[Hammer1-1]

On 10/7/2025 at 2:11 AM, lothar29 said:

Just one question... is there any way to heat the oil faster?

you could PROBABLY dilute the oil by using the cold weather oil priming method by dumping some fuel into the oil. Been a LOOONG time since Ive flown the 109, but IM fairly certain theres a fuel injection button specifically for oil dilution which thins the oil out briefly. You can always give that a shot, see if it helps, but the best method for heating an engine up is to just run it at high idle (1100-1500RPM) for a few minutes while you do your taxiing and flight prep. There is no realistic way to heat the oil faster.

Edited October 8 by Hammer1-1