Hello everybody,

I have a Octavia Mk3  2.0 (MY2019)  with SCR system (AdBlue). I have been monitoring the DPF for some time with VagDPF and I would like to know your opinions. Currently in Oil Ash Residue the value is 20.71g (same value in VCDS) and the car has 45546 miles. I don't know why, but I have the impression that the value goes up too fast.

For example with 44946 miles I had a value in Oil Ash Residue, of 20.45g. Doing a calculation it turns out that the value has gone up 0.26g in 600miles (0.00043g/mile).

I usually make short trips of 32 miles with 15% city + 85% highway. I always keep an eye on the VagDPF and try never to interrupt the regeneration. They usually start when the Soot Mass Calc value reaches 24 - 24.5g and I do them on highway with 4th gear at 2000-2500RPM.

I have looked at the upper limit of Oil Ash with VCDS and it is 80g. Using the values from the calculation, theoretically with 0.00043g/mile, I can get to 184000 miles with the Oil Ash value at 79.73g. I don't know if it's a very good value.

As a side note, I always use Shell V-Power, BP Ultimate fuel. Sometimes I use normal fuel but I add AR6900-D MAX  additive (1ml/L). As it consumes little AdBlue, I always use OEM and 0W30 oil (Shell, Ravenol, OEM).

I don't know if this is relevant, but I tried the Carista app and "playing" with the app, I accessed the "Emissions tests" menu and by mistake☹️ I pressed the "Reset button" and since then I am not calm. I don't know if this could have affected some parameter of the ECU regarding the DPF. I have performed several scans with VCDS and I have no fault codes.

Many thanks

Best regards🤝

Ignore it, it is a fictional calculated figure, if you look through the thousands of VCDS parameters you will find one where the grammes per km can be altered, likely there will be many and also with contrary names, only one is for your vehicle if at all.

You can also reset the oil ash value to zero even with a completely clogged DPF showing how ridiculous it is to be guided by the value of the measuring block.

The only one that concerns me is the increase in particle filter differential pressure over time/distance.

My DPF has moved a long way towards becoming clogged witnessed by the rising differential pressure readings, its because I was scammed into buying engine oil that claimed to be low SAPS but isn't, yet the oil ash figure is that of a car with very few miles on it, the amount of miles it has done since I asked myself "I wonder what would happen if I reset this to zero?"

The only way to get a zero or close to zero reading is to get the DPF professionally flushed out and then reset the counter. I'm also not a fan of low ash oil. Good regular oil changes will keep the car running as it should do and an occasional run of some super diesel through the vehicle and long fast runs will keep the EGR and DPF happy.

9 hours ago, varaderoguy said:

I'm also not a fan of low ash oil.

For what reason?

Regarding the use of "also" I have not said that I am not a fan, indeed I now know from experience that it is essential for my vehicle.

I'm not a fan, because IMHO its proved not to make that much difference in running the car. I'm far more a fan of regular oil changes for keeping the engine clean and functioning correctly.

Thanks to both of you for responding. I've been a bit busy these days and haven't been able to connect to the forum.

Theoretically, the more clogged the particulate filter is, the more the differential pressure increases. But is there an upper limit value that might indicate that the particulate filter is severely clogged/damaged?

Searching online, I found some data here, but I don't know if it applies to any type of engine.

Here's a screenshot of the VAGDPF regenerating the particulate filter. The highest differential pressure recorded is 125.

Best regards.

Edited 5 April, 20251 yr by FSKO