AVF Coal Development

Guest Free account, no CAN development support

Hello,

I have a question regarding a VW Passat 3BG, manufactured in 2005 with engine code AVF and 411,000 km.

Since the tandem pump was renewed (due to the leakage of the vacuum pump)
Increased soot formation during acceleration.

The fault memory has no entries, and the performance is okay for me.

Is there a possible connection to the replacement of the tandem pump?

Too much soot would mean too little air, from my understanding.
Air mass sensor between 250 and LL, max 1230
Maximum pressure: 2100 mBar

Initial inspection of the intake system without findings.

How can I narrow down / solve the problem?

Best regards

Faxe

08-08-2016, 15:45 Subject: AVF Coal Development

[Translating...]

Also 1230mg/Hub @ 2100mbar passen nicht zueinander, da hast du eine Undichtigkeit in der Ladeluftstrecke.

08-08-2016, 18:37 Subject: AVF Coal Development

[Translating...]

Hallo Faxe,

bei dem Auto müsste ein Ladeluftrohr vorne quer unter dem Kühler auf die andere Seite gehen, die Bögen an dem Querrohr bitte auf Lecks prüfen.

Viele Grüße, Rainer

08-08-2016, 20:11 Subject: AVF Coal Development

[Translating...]

TDI-GTI-4-Motion wrote:

Also 1230mg/Hub @ 2100mbar passen nicht zueinander, da hast du eine Undichtigkeit in der Ladeluftstrecke.

Welcher Luftmasse würde hier passen?

08-08-2016, 22:00 Subject: AVF Coal Development

[Translating...]

Hängt natürlich stark von der Drehzahl ab, aber keinesfalls nennenswert mehr als 1050mg/Hub.

Translated on 03-07-2026, 15:19.

Given such a high power output per stroke, a "chiptuning" for a wood hammer might also be considered...

Translated on 03-07-2026, 15:19.

Hufe wrote:

Given such a high mg/stroke, a wood hammer "chiptuning" might also be considered...

No, because in that case the boost pressure would be higher. You can't press the same amount of air into the engine without getting a higher boost pressure.
The ratio of air mass to intake pressure is quite constant and depends on the engine's displacement volume. Small deviations are due to better or worse intake air cooling.

Best regards, Rainer

09-08-2016, 12:53 Subject: AVF Coal Development

[Translating...]

Richtig, 1230mg/Hub @ 2100mbar passt bei OEM HW einfach nicht zu dem Motor, Chiptuning hin oder her.

Der Lader drückt halt real deutlich mehr, nur kommt am Sensor eben nicht mehr an.

dieselschrauber · Translated on 03-07-2026, 15:19.

Hello,

yes, Michael and Rainer's assumption was correct, a 2cm crack in the fuel line behind the turbocharger.

new hose 3B0 145 828 G 113 euros at the dealer

The engine has no modifications.

Thank you for your help

30-09-2016, 20:31 Subject: AVF Coal Development

[Translating...]

Hatte auch nen AVF. Hab den Schlauch 3 mal getauscht. Immer wurde der hin, keine Ahnung wieso.
Selbst der Originale war nach 7 Monaten kaputt...