DPF regen questions/concerns

[John A]

I have a bit of an odd one, not related to my T6 but to my 2017 A6.

Tonight, I have interrupted a regen - this is probably the third or fourth in a row, where the car is idling at 1,000 RPM and the fan runs on when I switch the car off.

I checked measuring blocks on the way home which shows a calculated soot mass of 6.41g and measured at -5.31g (which doesn't look right to me).
The distance since last regen is approx 300km (or about 180 miles) but there is nothing in the measuring blocks that suggests the car is doing a regen.

Do I have a fault? There are no DTCs but I got 23.8mpg on the way home because clearly, there is some additional use of fuel to try and raise the temperature, but it doesn't actually look like it's doing anything.

Any thoughts?

 

[whodat]

I wouldn't worry about it for now.
Most owners don't look on forums, and just drive. Can you believe it? They don't spend their lives wondering when the DPF is having a regen or worry about EGR valves.
Unbelievable.

I'm a nervous wreck.

 

[Lubrown]

I wouldn't worry about it for now.

Me either.
We have the same thing as OP with our Golf. It’s now on 109k miles (10 years old) and never had a problem with the DPF despite getting used for pretty short journeys too often and despite being switched off during regens.
Hopefully I haven’t jinxed it!

 

[Dellmassive]

Have you tried letting it complete it's regen,,?

At the end of the journey, just sit there at idle, the regen should finish after 15,mind or so... Or the revs will drop back down again.

More info..

DPF Regen, Yellow Light & Adblue - Whats It All About? -

DPF Regen, Yellow light & AdBlue - Whats it all about? - The DFP light is becoming a more apparent issue with modern diesel vans, unfortunately, it’s a fact of modern diesel life. what is a DPF? Diesel particulate filters (DPF) are very effective in cutting emissions, trapping even the...

www.t6forum.com

.

 

[mmi]

I checked measuring blocks on the way home which shows a calculated soot mass of 6.41g and measured at -5.31g (which doesn't look right to me).
The distance since last regen is approx 300km (or about 180 miles)

Would be normal for T6 when it's at the end of regen cycle -then the distance would reset to 0 km.

there is nothing in the measuring blocks that suggests the car is doing a regen.

Please post engine blockmap data so we can have a look into what's available - as below

Fault code P0299 Boost - 2019 Crafter

Hi , i have a PO299 underboost issue i cant get to the bottom of. i have borrowed a copy of VCDS and ran the codes, its has stated as follows : vw crafter 2.0 - daua 2019 fwd drives fine98% of the time, but suffers a po299 underboost when crusing at about 65mph. drive fine under soft driving...

www.t6forum.com

 

[mmi]

At the end of the journey, just sit there at idle, the regen should finish after 15,mind or so... Or the revs will drop back down again.

Don't know the details about A6 but e.g. T6 doesn't finish DPF regen at standstill...

T6.1 Reduce oil level and Oil dilution

@totitxu, says: (Translated for the benefit of readership on the forum :thumbsup:) "I'm glad it helps you, I'm very happy with it, as you said, it warns you at the beginning and end of the regeneration and I have to say that the oil level remains at the same level as when they changed the oil...

www.t6forum.com

 

[roadtripper]

From observation using VAG-DPF (not the extensive data logging of @mmi) I'm certain that a T6.1 doesn't complete a regen at idle but gives up at around the 5 minute mark.

I still let mine run on though as my assumption (hope?) is that controlled pause to regen is not going to be dumping diesel into the oil.

While I take @whodat s point a DPF regen approach of injecting fuel to raise the exhaust temp (rather than an additive nearer the DPF) coupled with a design for long oil change cycles can have some nasty edge cases for folks wanting to run engines long term, so a little awareness is useful.

 

[Howzat]

From observation using VAG-DPF (not the extensive data logging of @mmi) I'm certain that a T6.1 doesn't complete a regen at idle but gives up at around the 5 minute mark.

I still let mine run on though as my assumption (hope?) is that controlled pause to regen is not going to be dumping diesel into the oil.

While I take @whodat s point a DPF regen approach of injecting fuel to raise the exhaust temp (rather than an additive nearer the DPF) coupled with a design for long oil change cycles can have some nasty edge cases for folks wanting to run engines long term, so a little awareness is useful.

My T6 often does this at idle or low revs. If I restart the engine the regen will continue then eventually complete.

 

[Alster]

My 6.1 doesn’t complete a regen at idle-the revs drop after about 5 minutes but it then carries on on the next run

 

[Gsixty]

My 6.1 doesn’t complete a regen at idle-the revs drop after about 5 minutes but it then carries on on the next run

Mine does this also. And Im with @roadtripper that it wont be dumping diesel into the cylinders then draining into oil. In fact if I switch off and get out and notice the heat/smell of a regen I get back in, start the engine again to hopefully stop the diesel being left time to drain into the oil. Im assuming it takes more that a couple of seconds to drain past.

 

[John A]

Have you tried letting it complete it's regen,,?

At the end of the journey, just sit there at idle, the regen should finish after 15,mind or so... Or the revs will drop back down again.

More info..

DPF Regen, Yellow Light & Adblue - Whats It All About? -

DPF Regen, Yellow light & AdBlue - Whats it all about? - The DFP light is becoming a more apparent issue with modern diesel vans, unfortunately, it’s a fact of modern diesel life. what is a DPF? Diesel particulate filters (DPF) are very effective in cutting emissions, trapping even the...

www.t6forum.com

.

I did once yes, and it didn't seem to do anything so I gave up!

Don't know the details about A6 but e.g. T6 doesn't finish DPF regen at standstill...

T6.1 Reduce oil level and Oil dilution

@totitxu, says: (Translated for the benefit of readership on the forum :thumbsup:) "I'm glad it helps you, I'm very happy with it, as you said, it warns you at the beginning and end of the regeneration and I have to say that the oil level remains at the same level as when they changed the oil...

www.t6forum.com

You can force a regen at standstill using VCDS and (I believe) a combination of pedal action, but the car has to be hot.

I was just curious really as this is the first EU6 car I've had (actually our Qashqai was probably EU6, but had done no miles) and I feel like it regens - or at least tries to - a lot.
The economy is pretty poor for the Ultra TDI engine. I have driven these before and seen nearly 70mpg. I'm not expecting that but I am not getting much better than 30 at times - maybe 40-42 on a 60 mile run at 60mph, so it makes me wonder if at every journey it's using fuel by trying to regen.
I've also not seen negative figures for soot so that also made me wonder if all was well.
I've got anti-crystallisation stuff in the Ad Blue tank, I use Archoil fuel additive and I've run a DPF cleaner through it. Twice I've had 50 mpg out of it on a 120+ mile journey.