Technical DPF or Sensor issue?

[lycopersicum]

Can you quote several pressure readings in context? Idling, accelerating, what speed etc. A single number is not informative enough.

I feel your dilemma, in the absence of the whole AdBlue delete thing the DPF would be a strong suspicion but the possibility of an unfortunate interaction with the deleted system is another strong possibility.

Once you get to this stage 2 blockage error I think you need to have the error cleared to enable another regen attempt or to indeed try any solution at all, as it's meant to force a visit to the dealer.

 

[Killykix]

We’re at a garage here in Greece. They did a forced regeneration (already our 4th one in 3 months). No soot in pipe. DPF is clean and not breached. We drove for 20min at highway and in cities, but no error fault. However, we’re convinced problem will come back.

 

[lycopersicum]

Okay. Assuming your engine is healthy and not producing abnormal amounts of soot. From this point, if your DPF is healthy, it will need a regen in about 800 km. Let's say 700 to 1200 depending on your driving conditions.

- if the error comes back in less than 700 km, the DPF probably needs changing. Or at least taken off for a deep clean in a special machine. This is not guaranteed to succeed but it can be a good occasion for the technician to evaluate the health of the DPF.

- if it comes back in more than 1200 km, and especially if the soot load is never going down, that would tend to indicate that the DPF has a normal ability to store soot and the issue is more with the regen not running properly.

- if it's in-between, it could be either.

You need to make sure your pressure sensor is working right, it should read close to zero with the engine off, respond smoothly to the gas pedal, and increase with engine load towards something in the 20 to 100 mbar range.

 

[jackwhoo]

Looking at figures in photo of scan tool .....
Average of last 5 driving regeneration times 5990seconds that is not normal

@lycopersicum

 

[Killykix]

Looking at figures in photo of scan tool .....
Average of last 5 driving regeneration times 5990seconds that is not normal

@lycopersicum

Yes, we also noticed it. We interpret it as if the car system has been trying to do the regen, but never succeeded. If this interpretation is correct, we need to understand why can’t the car launch successful regenerations. Maybe the temperature is never high enough? But not sure why…

 

[Killykix]

Okay. Assuming your engine is healthy and not producing abnormal amounts of soot. From this point, if your DPF is healthy, it will need a regen in about 800 km. Let's say 700 to 1200 depending on your driving conditions.

- if the error comes back in less than 700 km, the DPF probably needs changing. Or at least taken off for a deep clean in a special machine. This is not guaranteed to succeed but it can be a good occasion for the technician to evaluate the health of the DPF.

- if it comes back in more than 1200 km, and especially if the soot load is never going down, that would tend to indicate that the DPF has a normal ability to store soot and the issue is more with the regen not running properly.

- if it's in-between, it could be either.

You need to make sure your pressure sensor is working right, it should read close to zero with the engine off, respond smoothly to the gas pedal, and increase with engine load towards something in the 20 to 100 mbar range.

Very interesting. Last time we did a forced regeneration, we drove around 1200km before it came back, from Bulgaria to Southern Greece.

Have you seen the picture I attached earlier (hereby attached gain)? It does seem that the car system doesn’t manage to run regen (last time it tried for 1h40 regen instead of 15min), but we can’t understand why.

It believe pressure sensor is working properly. The garage just reset it again, it’s brand new and gives low reading when idle.

We will anyway follow your advice and go to a DPF cleaner. I guess it can only be beneficial, although I’m not sure it’ll solve the issue (if regen isn’t happening, a clean DPF won’t help)

 

[lycopersicum]

Interesting indeed. Are you able to monitor the soot load while driving? Eg if the error comes after 1200 km and no regen attempt (soot load just keeps increasing) the DPF itself could be fine, the problem is elsewhere. Vs coming after 1200 km but several regens in that interval (soot load goes down, but creeps up higher every time), then DPF is a likely culprit.