DPF Fehler - 19226 - Partikelfilter Bank 1 P2002 | Posts 16+

Herbert wrote:

Hi, I would have been curious to know what that junk was. hg Herbert

Hello Herbert,

Most likely urea, which, after reacting with exhaust gases, can accumulate undisturbed in that area because the volumetric flow in this region is neither large nor constant.

Best regards, Witalij.

Hi everyone,

I can't entirely agree with that opinion...

I would define "Schmodder" as referring to poor fuel quality with a high sulfur content, often associated with biodiesel (B7, B10, or higher), where rapeseed oil is primarily used as an additive.
trace back!
Depending on the mechanical condition of the engine, the quality of the engine oil can also play a role.

AdBlue (colorless) contains over 60% demineralized water in addition to urea, which is ultimately converted into nitrogen in the SCR catalyst. This means that calcium can precipitate out of the solution.
I would rule out urea as the cause; the yellowish color suggests this conclusion.

Best regards, Richard.

Okay, urea is out.
He uses Meguin oil, after getting approval, and the consumption is approximately 0.5 - 0.7 liters every 30,000 km.
I usually fill up the tank in Denmark. It feels like the diesel quality is better there than in Germany, as I often drive 50-100 km further on a single tank of fuel.
As far as I know, they only have B7 diesel there.
If the problem were due to fuel, it would likely be more widely known.
My next guess would be that it's a product of the Russian combustion process, but I can't quite figure out how it got behind the EGR valve, as that valve is supposed to be closed during regeneration.
It's noticeable that this substance is only found in and after the AGR cooler, nowhere else.


Best regards,

E30_V8 wrote:

Hello everyone, AdBlue (colorless) contains over 60% demineralized water in addition to urea, which is ultimately converted into nitrogen in the SCR catalyst. This means that calcium can precipitate out of the solution. I would rule out urea as the cause; the yellowish color suggests this conclusion. Best regards, Richard

Hello again,

My assumption isn't as far-fetched as it might seem, because...
If the complete decomposition of urea is not achieved, solid deposits of cyanuric acid (a trimer of isocyanic acid) or melamine (melamine is a white, odorless, and tasteless powder) can form through the intermediate product, isocyanic acid, which can lead to blockages in the exhaust system.
And it is precisely in this area that complete decomposition is hardly possible due to the design, as a closed valve temporarily creates a dead end, while simultaneously, the exhaust gases are cooled by the EGR cooler.

Best regards, Witalij.

Hi,
Am I correct in understanding that the first images show the position motor 2 (V339) for exhaust gas recirculation, located on the exhaust gas recirculation cooler? The portion of the recirculated exhaust gas that is controlled by this motor is diverted after the diesel particulate filter (DPF). And does the first injection of urea take place before the DPF?
Could you please tell me exactly what the first four images depict?
My humble suggestion is that the "gunk" might also be coming from the particulate filter.
hg
Herbert.

Herbert wrote:

Hi, Am I correct in understanding that the first images show the position motor 2 (V339) for exhaust gas recirculation, located on the exhaust gas recirculation cooler? The portion of the recirculated exhaust gas that is controlled by this motor is diverted after the diesel particulate filter (DPF). And does the first injection of urea take place before the DPF? Could you please tell me exactly what the first four images depict? My humble suggestion is that the "gunk" might also be coming from the particulate filter. hg Herbert

Hi,

It's exactly as you described. The first four pictures show the AGR valve in both the removed and installed states.

I've added a picture; the arrows indicate the following.
Red; Urea injection valve.
Yellow; DPF.
Green; AGR cooler.
Blue; EGR valve.

Best regards,