DPF issues (sorry)

[dowding]

So. I purchased my 2015 octy vrs cr last week and noticed the regens are happening everytime I drive the car. I plugged her in and no fault codes, so Vag DPF shows the car has a fault (red exclamation point next to a timer) the car seems to do a full regen......which takes nearly 40 mins of driving.....then clears until I restart the car, then the car runs as expected for a minute or 2 then the soot jumps up to 100% full or more. I have changed the dpf exhaust pressure sensor and reset the values in vcds but no joy. Can anyone tell me what else I can do to solve this please? Its driving me mental.....pun intended. I have attached a video to show what I mean.......any help would be amazing. Cheers all

[Ecomatt]

If you purchased from a garage then take it back for them to fix or fit a new one. The garage has a responsibility in law for any fault that happens during the first 6 months under the Comsumer Rights Act 2015.

[dowding]

Unfortunately the garage is 200 miles away and they do not have repair facilities. The car is covered by a warranty that only covers engine and gearbox failures. 

[BogdanB]

Have been in exactly the same situation, with warranty covering only the engine and gearbox and having a blocked DPF.

 

What is triggering the regens is the soot mass measured, that cannot be seen in the current selected engine group ( you see NOX sulfur charge instead). Go to settings, and choose Custom Engine Group ( Group 0) and you will be able to see why those soot jumps happen.

 

As for a fix, you will 100% need a DPF clean, which depending on where you live, might be expensive or relatively cheap. 

Also, does your car use any abnormal quantity of oil ? Since the DPF shouldn't be blocked at that mileage. And did someone fiddle with the values on your DPF? It shows 0.0g of Ash which is only valid for a new DPF.

Edited 31 May, 2022 by BogdanB

[J.R.]

They have done a good number on you and you have swallowed it.

 

You will wise up on their responsabilities and not letting them use the warranty to bin you off but they will probably use the 200 mile distance problem to wear you down, also the work that you have done yourself.

 

Video will not play for me.

 

Sounds like the DPF is clogged but you have reset the values so it will show as empty which does not help you, what is the differential pressure at tickover and the 3.5k rpm static rev limit?

[MarkyG82]

100k miles could easily have clogged the dpf. Particularly if the recent miles/years before you taking ownership were sedate. Which is quite likely given what the world has been through the last couple of years.

Lots of people trading in diesels and others getting "good deals". I changed away for the same reason and do miss the car. But the risk of having a big bill (and subsequent time off the road) was too big.

 

To solve this you will likely need to pull all the sensors and confirm the function and health of them. Once confirmed to be trustworthy you can then start to see the actual issue. A filter out clean or replacement sounds to be the most likely solution.

[BogdanB]

Selling the car with a blocked DPF should be made illegal... 

If it's not very expensive, I'd suggest straight up cleaning it first, since it won't do it any harm considering the mileage.

[Ecomatt]

5 hours ago, dowding said:

Unfortunately the garage is 200 miles away and they do not have repair facilities. The car is covered by a warranty that only covers engine and gearbox failures. 

The responibility of the garage does not stop with whatever warranty they offer. By law they are responsible for any fault that happens during the 6 months. I would speak with the dealer owner and mention the issues and also quote the Consumer Rights Act 2015. If they use the 'we do not have repair facilities on site' then they are by law obligated to pay for your car to be repaired at a garage. If not I would mention Citizens Advice and also small claims court. You would win a claim easily but you have to offer them the chance to rectify it or reject it for a full refund in the first 28 days.

 

[fr1nklyn]

21 hours ago, Ecomatt said:

The responibility of the garage does not stop with whatever warranty they offer. By law they are responsible for any fault that happens during the 6 months. I would speak with the dealer owner and mention the issues and also quote the Consumer Rights Act 2015. If they use the 'we do not have repair facilities on site' then they are by law obligated to pay for your car to be repaired at a garage. If not I would mention Citizens Advice and also small claims court. You would win a claim easily but you have to offer them the chance to rectify it or reject it for a full refund in the first 28 days.

 

 

I hope that one day that will work in my country as well  

 

If that didn't work, try cleaning it first. It costs like £200-300 compared to £1500 or so for a new DPF.

 

Usually a DPF could be cleaned once or twice before replacement. But due to a rust formed by the harsh chemicals used for the cleaning, sometimes only once...

[BogdanB]

34 minutes ago, fr1nklyn said:

 

I hope that one day that will work in my country as well  

 

If that didn't work, try cleaning it first. It costs like £200-300 compared to £1500 or so for a new DPF.

 

Usually a DPF could be cleaned once or twice before replacement. But due to a rust formed by the harsh chemicals used for the cleaning, sometimes only once...

 

Cleaning can also be done with pressure washing. No harsh chemicals involved.

EDIT:  Disclaimer->As far as I know.

Edited 1 June, 2022 by BogdanB

[dowding]

I have now changed the differential pressure sensor, MAF, map and reset all the values on vcds. Yes I reset the ash to 0 to observe when the DPF regen starts. It was on 5.0 when I got the car. I notice when I boot the car it happens but if I go slow the spike doesn't go up and the DPF acts normally. The other think I noted was when the spike in soot happens the injector values jump up as pictured. I have emailed the company and asked them to have the car fixed as it's not road worthy at present. The oil is becoming contaminated and it's doing 40mpg on a run which is awful. No reply from the garage but I'll report them to trading standards if they don't reply. 

 

Could the O2 sensor be at fault? When I got the car there was a leak between the turbo and cat which just needed the clamp tightening up as it was loose. 

 

Cheers for the replies guys 

[BogdanB]

Is that picture at tickover? Or while driving?

 

If it's at tickover, the differential pressure is HUGE. Mine never gets past 35-40 hPa ( and this would be at 100% DPF load ). After a regen it sits at around 6-12hPA.

 

All values that I've mentioned are at tickover ( 750 rpm stationary)

Edited 3 June, 2022 by BogdanB

[J.R.]

Clogged solid, diff pressure through the roof 25g calculated soot load 3km after a regen.

 

When I tested mine the other day the calculated soot load was 15g, measured was 3g, tickover diff pressure was low (cant recall but was in single figures) rising to 35Hpa at 3.5K rpm.

Edited 3 June, 2022 by J.R.

[bigjohn]

Take it back:- 

https://www.theaa.com/car-buying/legal-rights

[dowding]

Those figures are at full chat. The car does a regen then the g/km spikes at around 24000 g/km for litterly 1 second and the DPF goes into regen again. Surely this is a sensor error? 

[dowding]

On 31/05/2022 at 10:12, BogdanB said:

Have been in exactly the same situation, with warranty covering only the engine and gearbox and having a blocked DPF.

 

What is triggering the regens is the soot mass measured, that cannot be seen in the current selected engine group ( you see NOX sulfur charge instead). Go to settings, and choose Custom Engine Group ( Group 0) and you will be able to see why those soot jumps happen.

 

As for a fix, you will 100% need a DPF clean, which depending on where you live, might be expensive or relatively cheap. 

Also, does your car use any abnormal quantity of oil ? Since the DPF shouldn't be blocked at that mileage. And did someone fiddle with the values on your DPF? It shows 0.0g of Ash which is only valid for a new DPF.

It seems the calculated soot drops while the measured is staying the same. The measured only drops if I idle the car. The regen completes, then I drive the car and the measured goes up very quickly followed by the spike to 100% full. 🤔

[Ecomatt]

If the soot (oil ash) mass was at 5.0g when you first got the car. It sounds like the last owner reset it

My oil ash mass is at 37.5g at 88600 miles. I would presume it was reset to prevent a dpf light from activating. Either that or the last owner got it cleaned but I cannot see someone spening a few hundred pounds only only to sell it. 

[J.R.]

Its clogged!

 

You could try an adaption channel that resets the differential pressure sensor to  atmospheric pressure and in doing so changes the DPF offset, it's normally only something that would be done with a new sensor but worth a try.

 

What does it show the pressure at with the engine not running? It should be close to zero milllibars.

[J.R.]

5 minutes ago, Ecomatt said:

If the soot (oil ash) mass was at 5.0g when you first got the car. It sounds like the last owner reset it

My oil ash mass is at 37.5g at 88600 miles. I would presume it was reset to prevent a dpf light from activating. Either that or the last owner got it cleaned but I cannot see someone spening a few hundred pounds only only to sell it. 

Soot is usually a different parameter to oil mass or ash but they keep changing the names of the parameters even within the same version of VCDS not to mention the measuring units be they volume or mass or mass measured in volume units etc etc, kms expressed in metres etc, it's a wonder that anyone can make any sense of it.

 

Then there are the parameters expressed and units used in the phone app which despite sounding like it is something from VAG I bet that it isn't, I am very wary of what it claims to show given the limited parameters that are measured but thats only as a cynical observer and not a user, certainly VCDS is pi55 poor.

[J.R.]

I reset my oil ash volume or whatever its called today to zero and that's where it has stubbornly remained, I'm sure that I have done over 10K kms or miles since, I suspected that it only increased in those units as it seemed to match gram per 10K kms, was always a round figure and would go up 1 unit per 10K.

[dowding]

4 hours ago, J.R. said:

Its clogged!

 

You could try an adaption channel that resets the differential pressure sensor to  atmospheric pressure and in doing so changes the DPF offset, it's normally only something that would be done with a new sensor but worth a try.

 

What does it show the pressure at with the engine not running? It should be close to zero milllibars.

I tried that as I changed the differential sensor 1st. Is it possible the car is badly mapped causing massive soot output? It feels very quick when it's not doing a regen. 

 

[J.R.]

Its blocked.

 

I ask again, what is the differentiel pressure at idle?

[dowding]

8 hours ago, J.R. said:

Its blocked.

 

I ask again, what is the differentiel pressure at idle?

3 on engine off, 41 on idle

[J.R.]

Your DPF is blocked.

[MarkyG82]

I think this and another thread a couple of weeks ago show that no amount of want from the owner will unblock a dpf. Just get it cleaned or replaced. Part of owning a modern diesel unfortunately.