CRMB 2.0 TDI Euro 6 DPF, approximately 242,000 km, fully clogged?

Hello,

I have a Skoda Octavia 5E facelift 4x4, manufactured in 2018.
Engine code: CRMB 2.0 TDI 150 hp, without AdBlue.
Mileage: approximately 242,000 km (mostly long-distance driving).
Oil ash content: 61.5g
Limit: 80g.

Oil consumption: approximately 1 liter per 10,000 km since first delivery.
It now regenerates approximately every 70 to 120 kilometers... The soot mass, which was initially calculated to be between 8-11g, jumps to over 22g and then begins to regenerate.

"Under normal driving conditions, regeneration can take a very long time, sometimes up to 40 to 60 minutes." The amount of soot decreases very slowly, even starting from around 5-6 grams.

Differential pressure according to VAG DPF: maximum 300 mbar, approximately 10 to 15 mbar at idle shortly after regeneration. When accelerating "from higher RPMs" (above approximately 3000 RPM), the power feels somewhat weak. However, I'm not sure if this is simply due to the all-wheel drive system, as I don't have a comparable vehicle for comparison. (A Golf 1.6 TDI with around 130 horsepower easily pulls away from me.)

Since two identical differential pressure sensors are installed, I have already swapped them, but I couldn't detect any differences.

No errors are stored in the control unit.

Can we conclude from this behavior that the DPF is simply full due to the constant oil consumption (which is, after all, about 40 liters)?

I would be very grateful for any advice.
Thank you & best regards.

Hi,

Quote:

Can we conclude from this behavior that the DPF is simply full due to the constant oil consumption (which is, after all, about 40 liters)?

Quite likely, yes.
You can view the "Soot mass measured" value before, during, and after the regeneration process. When the value exceeds just over 23 grams, regeneration is triggered, regardless of which value, measured or calculated, first crosses the threshold.
The ash content is calculated based on the Kjeldahl nitrogen content and may also be too low.
I have 51 grams of oil consumption for 180,000 kilometers, and that's with significantly less topping up.
hg
Herbert.

Thank you for the quick response!

I will also take a look at the values mentioned.
What are the typical mileage intervals between recharges?
Is a DPF cleaning service, for example, offered by a company like Barten GmbH (using a thermal-mechanical process), likely to be successful? Or is there anyone in the forum who has experience with this topic?
Should other components be replaced or cleaned at the same time as the DPF is replaced? (e.g., high-pressure EGR valve, lambda sensors, DDS, etc.)

Sure, here's the translation:

"LG" translates to "Best regards" or "Sincerely" in English.

Hi, Hello,
"In my experience, regenerations have always been triggered when the calculated soot mass exceeds the limit." The calculation is mainly consumption-dependent. A high exhaust gas temperature at a high exhaust gas flow rate reduces soot formation (like during highway driving). I typically drive around 450 km between refills in the summer.
In my humble opinion, your DPF is no longer being properly cleaned. As a test, try cleaning it as described in this forum, or even better, replace it with a genuine part, preferably along with new sensors. "He who saves may end up paying twice if he's unlucky."
hg
Herbert.

Hello,

You might find a comparable vehicle here regarding differential pressure.
Okay, I'm ready. Please provide the German text you want me to translate.

I don't necessarily consider your value to be unusual, depending on the engine, the fill level of the DPF, and the performance.

I would check the intercooler piping for leaks (leaks often appear as oily spots), because in addition to increased exhaust gas recirculation, which fills the DPF much faster, it also causes a loss of power.

Best regards, Rainer.

Hello,

Thanks for your input.

I couldn't find any oily spots on the intercooler system, as far as I could see.

However, I've taken a closer look at the measured and calculated soot mass during the journey:
The measured value increases very quickly and always triggers the regeneration process. (For example: freshly regenerated -> measured approximately 5 to 8 grams, calculated 1.73 to 4 grams; shortly before regeneration -> measured 21.3 grams, calculated 6.77 grams).
During the regeneration process, the measured value decreases very slowly from approximately 6 to 8 grams, or in some cases, even increases again. It consumes approximately 4 to 5 liters of diesel before it starts regenerating again.
The differential pressure, even at full load and speeds exceeding 4,500 RPM, does not exceed just under 300 mbar (even after multiple attempts).

Is the measured soot mass determined solely by the DDS (Diesel Particulate Sensor), or do other sensors also play a role? Assuming the DDS values are correct, where could the high soot levels be coming from, and how can I identify and rule out potential sources of error? Of course, I have the full version of VCDS.


Thank you & best regards.