Oil Consumption: Turbo vs. Piston Differences

Hello, yesterday I had an AFN/AVG Galaxy with approximately 240,000 km. I used a mixture of Aldi oil occasionally, but not for a long time now. It has 110 horsepower.
"Due to a fault code indicating a problem with the boost pressure regulation, the system was scanned. Due to time constraints, only a small hole in the boost pressure hose was found, which had been chewed through."
repaired and errors removed.
Boost pressure was reached at 2300, but was weak below that level.
I advised him to avoid running the engine at very low speeds initially, to prevent it from entering a limp mode.
Today, while on a vacation trip, I drove 100 km with 30 km/h on the highway when suddenly the engine lost power, like it went into a limp mode. Then, the engine started running without me pressing the gas pedal, exceeding 4000 RPM. I pulled over to the side of the road, and that was the end of the trip.
Towed away without further action; oil level below minimum.
I suspect a piston crack or turbo oil leak.
What's the most sensible approach to take now, given that I don't have a compression tester?
Could you bring that box over to me? Is it possible for the turbo to lose that much oil without exploding?
Added 1.5 liters of engine oil at home, and the level is now 3/4 full.
The engine, which was cold, started again with a puff of oil smoke.
Then, no more clouds over LL.
No foreign noises when the engine is idling.
Der neue T5 soll im März kommen, also erstmal abmelden? How to sell?
Okay, let's start by assessing the extent of the damage...

teileklaus wrote:

I suspect a piston ring issue or turbo oil leak.

teileklaus wrote:

No foreign noises when the engine is idling.

Therefore, I doubt it's a Koben issue. Have you had a chance to examine Turbo yet?

Thanks, I thought maybe the crack in the cooled piston would have shrunk back together after 1 hour? I don't have any experience with that.
No, FZ is playing away.

teileklaus wrote:

Thank you, I thought that the cooled-down crack in the piston might have shrunk back together after 1 hour??

So, if that's a crack, then how can it draw so much oil to reach speeds well over 4000 RPM? If it's there, it must also be present even when the engine is cold.

You could perform a simple compression test, perhaps using a 'hop' test.

Hi,
"If the engine revs up without any throttle input, it must be burning oil in some way to achieve that increase in speed. However, that shouldn't be possible, at least not in the cylinder with the supposedly damaged piston, right? And the idea that the blow-by gases are then pushed through the intercooler into the other cylinders, especially considering the currently normal idle noise, I find unlikely. It's probably the turbo..."

Best regards from Berlin,
olli

I'm not sure, but I imagine the piston is starting to crack. It was running smoothly before, but now combustion gases are leaking into the crankcase and being drawn in again, causing further combustion. A liter is quite a lot.

I once had an LT engine where the piston was severely damaged, and it didn't consume any oil.
Just disconnect the intercooler piping, and then everything will be clear.

teileklaus wrote:

I don't know, I imagine the piston starts to crack, before it was running fine, combustion gases go into the crankcase and are sucked in again, and burned. 1 liter is quite a bit.

Not impossible, but extremely unlikely.

Quote:

I don't know, I imagine the piston starts to create a crack, before it was running fine, combustion gases go into the crankcase and are sucked in again, and burned. 1 liter is quite a lot.

If the piston has a crack, the combustion pressure (due to the shape of the piston bowl) will also push it outwards, which will definitely cause scoring on the cylinder wall, and then it will also...
The cooling system is not working properly anymore.

Therefore, as mentioned before, disconnect the turbo and let the engine warm up.