Formsand in der Ladeluftstrecke? | Posts 16+

matthiasTDI96 wrote:

... I have to disagree with Bertil on that point. ....

Where are you disagreeing with me?
I don't see anything there... At least, not regarding the casting process and the foundries.

Quote:

... You should see what the intake air paths look like in vehicles that use dry cotton filters (sport air filters). You'll find a kind of "grinding paste" buildup in the quieter areas, such as hose connections, intercooler, etc. Surprisingly, these engines often last well over 100,000 km. ...

My AXR has almost 250k miles... with a K&N filter since 15k miles... the turbo is original, the MAF sensor is original... but the clutch is the fifth one!

ulf wrote:

... Meine GAU-Gedanken gehen auch in Richtung verklemmter Krümel in Ventildichtsitzen: Wenn ein Ventil deswegen nicht mehr richtig schließt, können AFAIK glühende Abgase vorbeiblasen und es verziehen . . . oder liege ich da falsch?

You'll need a bit more than just a few crumbs.

Quote:

Da brauchst du aber etwas mehr wie so ein Paar Krümelchen .....

The crumbs will definitely be ejected at the latest during the next gas change.

"I used to encounter crumb problems more frequently in older (T)DIs with the ARF intake manifold issue. I would clear the channel by scraping and blowing it out without removing the catalytic converter, and only when the intake valve was closed."
During the subsequent test drive, the engines occasionally sputtered slightly if a small particle remained stuck between the valve and the valve seat.
Once the engine had warmed up after a few kilometers, it ran perfectly smoothly.

After that, the vehicles have generally run without problems, with some having exceeded 100,000 km, and I am not aware of any engine-related failures.

ulf wrote:

Meine GAU-Gedanken gehen auch in Richtung verklemmter Krümel in Ventildichtsitzen: Wenn ein Ventil deswegen nicht mehr richtig schließt, können AFAIK glühende Abgase vorbeiblasen und es verziehen . . . oder liege ich da falsch?

Well, you could also get struck by lightning while you're, uh, defecating.

But perhaps that's the key that Autobild was waiting for: The reason for the high oil consumption in various TSI engines is due to casting defects in the turbocharger manufacturers, who were pushed to their limits... Sand -> Defects -> Oil leakage