Soot Formation in AVF Engines

Hello,

I have a question about a Passat 3BG, model year 2005, engine code AVF, with 411,000 km on the odometer.

Since the tandem pump was replaced (due to a leak in the vacuum pump).
Increased smoke production during acceleration.

The error memory is empty, and the performance is acceptable to me.

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

As far as I understand, too much soot would mean there's not enough air.
Air mass meter readings between 250 at idle and a maximum of 1230.
Boost pressure up to 2100 mBar.

Initial inspection of the intake manifold revealed no issues.

How can I narrow down the problem / find a solution?

Best regards,

Faxes.

So, 1230mg/hub @ 2100mbar don't match, which means you have a leak in the charge air duct.

Hello Faxe,

The car needs an intercooler piping that runs horizontally across the front, underneath the radiator, to the other side. Please check the bends in that piping for any leaks.

Best regards, Rainer.

TDI-GTI-4-Motion wrote:

So, 1230mg/stroke @ 2100mbar don't match, which means you have a leak in the charge air duct.

Which air mass would be appropriate here?

It obviously depends heavily on the speed, but it definitely shouldn't be more than 1050mg per stroke.

With such a high mg/dose, a "chip tuning" modification using a wooden hammer might also be considered...

Hufe wrote:

With so many mg/dose, a wooden hammer "chip tuning" might also be considered...

No, because then the boost pressure would be higher. You can't force more air into the same engine without increasing the boost pressure.
The ratio of air mass to boost pressure is quite constant and depends on the engine's displacement, with slight variations depending on the effectiveness of the intercooling system.

Best regards, Rainer.

Right, 1230mg/stroke @ 2100mbar simply doesn't fit with the OEM hardware for that engine, regardless of any chip tuning.
The loader is actually applying significantly more force, but that force isn't reaching the sensor.

Hello,

Yes, Michael and Rainer's assumption was correct: there's a 2cm crack in the pressure hose located behind the turbocharger.

new hose 3B0 145 828 G, 113 Euros at the official dealer .

The engine is completely stock, with no modifications.

Thank you for the help .

I also had an AV fistula. I replaced the shunt three times. Each time, it failed, and I have no idea why.
Even the original one broke after 7 months...