Regenerated Skoda Octavia 2.0 TDI CR - Every 50km

Quote:

The customer reports several problems with the DPF regeneration process in their vehicle: Oil Overfill: The oil level rises again to the maximum level after approximately 2,000 km following a change. Smoke emission: During the regeneration of the diesel particulate filter (DPF), a significant amount of smoke is produced. Too frequent regeneration: Over a distance of 150 km, the regeneration process starts up to three times. No error codes: There are no corresponding error messages stored in the error memory. Problem similar to: TDI regenerating too frequently!? Measures already implemented: Injector Check: A specialized workshop inspected the fuel injectors; they were in good condition. A slight deviation was detected under full load, but it is not noticeable to the customer. DPF Cleaning: The diesel particulate filter was cleaned using a cleaning kit (DPF cleaner), the learned values were reset, and a service regeneration was performed. This did not result in success. Specific questions regarding the diagnosis: The customer has attached log files and is requesting assistance in interpreting the values. Why does the "calculated soot mass" increase so sharply and trigger regeneration? He considers the increase in the calculated soot mass to be unusually rapid. The values from the differential pressure sensor appear normal to him (max. 350 hPa); he requests an opinion on this. It is also noticeable that during the regeneration process, the actual air mass is approximately 200 mg per cycle above the target value. The question is whether this is significant. Vehicle: Skoda Octavia Scout, 2.0 TDI, 103kW, manufactured in 2013. The customer is confused and asks for help in analyzing the measurement data.

Hello,

DPF cleaners may not be effective if the DPF is completely full of ash. And if it is not completely full of ash, cleaning is usually not necessary (exception: a completely unsuitable driving profile combined with negligence).

You first need to determine whether the DPF is clogged with ash or if there is another problem.

Maximum ash content: see below.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Cleaning the DPF and background information:
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

At 240,000 km, under unfavorable driving conditions, the DPF (Diesel Particulate Filter) can be completely full of ash. However, with economical driving, especially on the highway, there might still be "space" available, and a different problem could be causing the constant regeneration.

I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Best regards, Rainer.

Is the exhaust pipe clear after the DPF?
Does it already have an SCR catalytic converter?

Hi,
Your particulate filter is probably simply full. This would be consistent with a mileage of 240,000 km.
The initial recording (before cleaning) already reveals the problem. The oil ash volume is nonsensically set to zero (meaning that value was manipulated). The actual ash load is interpreted as soot load, the measured value quickly exceeds the limit, and as a result, regeneration occurs too frequently.
Of course, the amount of ash produced wasn't reduced by adding some kind of esoteric substance. According to the manufacturer, it's supposed to help prevent soot formation. Metal oxides cannot be converted or further combusted using organic chemistry.
Therefore, even after cleaning, the recording does not yield a better result.
I consider the "jump" in the value of "calculated soot mass" to be normal; it occurs whenever the measured value exceeds the field limit.
Buy a new, genuine diesel particulate filter, and then you can also reset the ash mass to zero. No matter where you try to verschandeln it or buy a replacement, you'll likely end up back here.
hg
Herbert.

Herbert wrote:

The oil ash volume is nonsensically set to zero (so the value was adjusted). The actual ash load is interpreted as soot load, the measured value quickly exceeds the limit, and therefore, regeneration occurs too frequently.

Wasn't there something about the oil ash volume needing to be within a certain range, otherwise it would require regeneration too often?
"I'd like to try setting the ash volume slightly below the maximum loading limit, just for testing purposes. (On an older Passat 3C, it was 60g, and I would have set it to 55g. With yours, it will probably be in milliliters. Some vehicles used to have a limit of 175ml, but I don't know the specific limit for your car. Please look it up yourself)."
With this change, the system produces significantly more ash, which means less soot. Consequently, the regeneration process should occur less frequently.

Perhaps the previous owner had already exceeded the charging limit and therefore reset it to zero.

Most likely, the filter will become full and need to be replaced or flushed immediately after regeneration. Rainer once wrote a guide for this, which worked well for my old Passat.


Regarding oil thickening: This is likely due to frequent regeneration cycles. Your engine is suffering as a result. I hope you change the oil well before 10,000 km.

Regarding the smoke: I'm a bit unsure about the cause. I'm familiar with some smoke during the regeneration process. However, I haven't encountered smoke as strong as the one you described.

Hello.

Quote:

Oil overfilling: After an oil change, the oil level rises again to the maximum level after only 2000 km.

"During regeneration, fuel is injected very late in the cycle, which results in increased fuel entering the engine oil. Therefore, it's not surprising that this happens with continuous regeneration."

Quote:

Wasn't there something about the oil ash volume needing to be within a certain range, otherwise it would be regenerated too often?

Yes, I agree.

The most common cause of excessive soot (which ends up in the DPF) is a leak in the charge air system, so check that and the points that others have already mentioned.

Best regards, Rainer.