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MrMcFly79 Blaumann

Joined: 06/19/2010 Posts: 145 Karma: +17 / -0
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19-09-2021, 20:14 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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New car, new problems...
The car is emitting soot even though it has a particulate filter. How is that possible?
Yesterday, I experienced a loss of power in the lower RPM range, along with excessive soot. Today, I got a warning signal on the display indicating a problem with the particulate filter. I then took it for a regeneration drive, after which the warning sign disappeared, and the power was restored. It still just smokes, though... 
Translated on 03-07-2026, 15:19.
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matthiasTDI96 Profi-Schrauber

Joined: 02/27/2003 Posts: 5886 Karma: +251 / -0
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20-09-2021, 6:40 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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Very simple:
It smokes for two (or three) reasons.
You don't have enough air available for combustion.
2. you have too much fuel (which, of course, is also the case with 1  ).
(3. You might burn something that shouldn't be burned, such as motor oil.)
Now, it would only make sense to start looking for the error.
This includes checking the LD (likely referring to a specific component or system), air filter, pipes, radiator, etc.
Check the measurements. And read a little bit here. The solution is definitely here in this forum.
Definitely don't drive much anymore, because a DPF (Diesel Particulate Filter) can fail quite quickly under those conditions.
Translated on 03-07-2026, 15:19.
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MrMcFly79 Blaumann

Joined: 06/19/2010 Posts: 145 Karma: +17 / -0
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20-09-2021, 7:52 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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Hi there,
Thank you for the quick response.
I would also guess your reasons, but shouldn't the DPF filter the particles? Does the amount of soot make a difference?
I read that it's supposed to allow soot from burnt oil to pass through, but I have absolutely no oil consumption.
Translated on 03-07-2026, 15:19.
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MrMcFly79 Blaumann

Joined: 06/19/2010 Posts: 145 Karma: +17 / -0
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20-09-2021, 7:53 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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Hi there,
Thank you for the quick response.
I would also guess your reasons, but shouldn't the DPF filter the particles? Does the amount of soot make a difference?
I read that it's supposed to allow soot from burnt oil to pass through, but I haven't experienced any oil consumption.
Translated on 03-07-2026, 15:19.
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matthiasTDI96 Profi-Schrauber

Joined: 02/27/2003 Posts: 5886 Karma: +251 / -0
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20-09-2021, 8:48 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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The filter does not selectively filter out soot. It can retain particles above a certain size. If soot is being produced and escaping, as you can see, then the amount being fed into the filter is exceeding its capacity. You can adjust the filter over a short distance of just a few kilometers.
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MrMcFly79 Blaumann

Joined: 06/19/2010 Posts: 145 Karma: +17 / -0
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20-09-2021, 10:38 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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Oh, I wouldn't have expected that.
Here's a log from yesterday. If I'm interpreting it correctly, the boost pressure seems to be lagging. By the way, isn't 2.5 bar (approximately 36 psi) a bit too much for a 140 horsepower engine?
It would be very kind if you could take a look at it  .
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| 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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MrMcFly79 Blaumann

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20-09-2021, 17:39 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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ahem *cough* Ash residue 104 grams
Why is he even still driving?
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dieselschrauber Administrator


Joined: 04/12/2002 Posts: 18003 Karma: +784 / -0 Location: St.Gallen 2018 Volkswagen T6 
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24-09-2021, 7:29 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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MrMcFly79 wrote: | Oh, I wouldn't have expected that.
Here's a log from yesterday. If I'm interpreting it correctly, the boost pressure seems to be lagging. By the way, isn't 2.5 bar (approximately 36 psi) a bit too much for a 140 horsepower engine?
It would be very kind if you could take a look at it . | .
It's interesting that the original loader is still active.
Definitely too much.
Excessive soot at the exhaust pipe despite having a DPF: problem solved.
My condolences about the car; it looks like it's been severely damaged. Hopefully, the price is right.
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MrMcFly79 Blaumann

Joined: 06/19/2010 Posts: 145 Karma: +17 / -0
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24-09-2021, 9:09 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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ok, so you mean bad chip tuning?
What is its typical boost pressure?
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guste100 Profi-Schrauber


Joined: 07/27/2004 Posts: 2399 Karma: +435 / -0 Location: Mitte Schleswig Holsteins 2007 Volkswagen Passat Premium Support
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24-09-2021, 10:16 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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The boost pressure in VCDS is displayed as absolute pressure. In colloquial terms, "boost pressure" typically refers only to the pressure above atmospheric pressure.
The atmospheric pressure is approximately 1 bar, depending on the altitude.
That means that if VCDS displays an absolute boost pressure of 2.5 bar, that is only 1.5 bar of relative boost pressure or overpressure.
That doesn't sound too bad for the engine...
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MrMcFly79 Blaumann

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24-09-2021, 13:11 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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Yes, I know  .
According to my research, it's supposed to be around 2.3 or 1.3.
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dieselschrauber Administrator


Joined: 04/12/2002 Posts: 18003 Karma: +784 / -0 Location: St.Gallen 2018 Volkswagen T6 
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25-09-2021, 9:24 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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I assumed that the concepts of "relative" and "absolute" were already familiar. Even 1.5 bar relative pressure at 4000 rpm is too much.
Unless, of course, the turbocharger is different from the one typically used for the 140 horsepower versions.
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MrMcFly79 Blaumann

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31-10-2021, 14:04 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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Something's weird with the car.
What do you think about the torque limitation? It's set way too high. The soot limit is constantly at 378.2 in the attached log, which is still 60 Nm too much... Should I get it chipped?
After that, it doesn't feel like much... especially considering it only manages to achieve a maximum speed of 200 liters per hour on the track. Hey.
...and it also consumes too much fuel.
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chli1976 Profi-Schrauber

Joined: 11/29/2003 Posts: 872 Karma: +185 / -0
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31-10-2021, 16:13 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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Unfortunately, the tuner didn't seem to know what he was doing, judging by the values he was producing. And of course, no logs were created before or after.
VCDS
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MrMcFly79 Blaumann

Joined: 06/19/2010 Posts: 145 Karma: +17 / -0
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31-10-2021, 16:39 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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Hi,
Thank you for your feedback. What makes you say that?
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chli1976 Profi-Schrauber

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31-10-2021, 17:46 Subject: 2.0 TDI BPW Pump Düse A4 B7 smokes despite having a particulate filter |
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Normally, the torque limit is programmed to be the lowest value, but in this case, it's not (as it is in the original file). This can lead you down the wrong path when troubleshooting certain issues.
In your case, the smoke limit depends on the boost pressure; for engines without a DPF, it depends on the mass airflow sensor; and for V6 engines, it usually depends on the lambda value.
However, since the boost pressure looks quite good except in the upper range, but the smoke limit is lower than the torque limit, the programming wasn't done correctly. That high torque value is useless because the system will always use the lowest limit. Even the current high torque value won't help you much, because the conversion map (torque to fuel injection amount) probably only goes up to 420 Nm, but I don't remember the exact number.
Flash the original file and then re-evaluate the situation. It might already be too late to save the DPF.
VCDS
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