Is my DPF 'too full'?

[Cuiken]

So I bought a Carista and downloaded the DPF app (Dashboard | DPF Monitor for VAG). Useful wee badger for telling you how close you are to performing a regen.

It also tells you the 'Oil Ash Residue' value for the DPF in % which, I gather, indicates how far through its lifespan the DPF is(?).

Our van seems to regen quite often (at least once every 100 miles or so) and reports the Oil Ash Residue to be around %43. Are the two things related? At 43% oil ash residue, is my DPF causing any unwanted additional restriction etc?

Cheers,

Cuiken.

 

[Stay Frosty]

I reckon you've solved your clunk and have found something new to worry about!
I say this after experiencing my first EML panic attack and additional Adblu spanner of doom with 650 mile countdown while trying to holiday and already some 300 miles into France.
This is how I'm going to approach a clogged EGR or DPF if diagnosed when our camper goes into the local VW dealer this coming Tuesday for an ECG. I'm either going to have it crushed or more likely take the KY jelly with me and hope it doesn't hurt too much as they discuss the repair cost , what I won't do is lose anymore sleep worrying about what it might be after it let us down on holiday, basically it's on the naughty step.

 

[Cuiken]

Ha! If only I'd fixed the clunk:

Clunk clunk clunk

The castor and camber angle actually do make the top pin of the shock move around a lot , it would snap the shock mounting pin off if it were solid The garage who fitted the shocks for me took an intersting approach. They bolted down one side too tightly and left the other one not even...

www.t6forum.com

 

[True Romance]

What's your usage? Long runs or short journeys?

 

[Cuiken]

Mixed usage. Just seems to be doing it more often these days. Got a few long runs next week. I'll see how it does then.

 

[Garyde]

Very interested to follow this... I've been having the same symptoms, lots of regen's (or at least it feels that way) and my oil ash residue is approx 50g.

I've downloaded the app, and ran it a few times, but not had a chance to dig into understanding what the data is telling me.

 

[Sackmycook]

I reckon you've solved your clunk and have found something new to worry about!
I say this after experiencing my first EML panic attack and additional Adblu spanner of doom with 650 mile countdown while trying to holiday and already some 300 miles into France.
This is how I'm going to approach a clogged EGR or DPF if diagnosed when our camper goes into the local VW dealer this coming Tuesday for an ECG. I'm either going to have it crushed or more likely take the KY jelly with me and hope it doesn't hurt too much as they discuss the repair cost , what I won't do is lose anymore sleep worrying about what it might be after it let us down on holiday, basically it's on the naughty step.

If it's any consolation, my bloody Peugeot sailed through it MOT this morning, only to go into Limp mode and display an orange dpf dash light on the A1 at Gateshead. Currently sat in Sainsbury car park awaiting a Man in an Orange van.

 

[Cuiken]

So, been a while, but this is still bugging me. Seems to regen all the time. Grabbed this a couple of days ago where you can see a few bits of info (taken when engine was warm):




Soot value is at 28% full after on 12.49 miles? Suggests 50 miles between regens which seems to be roughly what we're getting and feels pretty frequent.

49.04g of Oil Ash Residue apparently equates to ~44.5% full/lifetime (if you click on the 'Oil Ash Residue' tile). I guess if I'm 44.5% through the lifetime of the DPF (given 70k miles) that's probably fine. I'm just curious if there is any problem associated with running with higher Oil Ash Residue values?

I've read stories about a certain Oil Ash Residue value triggering a need for DPF replacement for example?

Cheers,

Cuiken

 

[mmi]

Soot value is at 28% full after on 12.49 miles?

I'd say the app calculates the percentage incorrectly.

For your engine the soot (calculated) range is from 6 to 24 grams. Regen starts at 24 grams (soot calculated) and finishes at 6 grams. Thus 18 grams to play with (actually a bit more as soot can go below 6 grams because of still hot DPF immediately after active phase of regen.

Thus 8.33 grams --> 2.33 grams above minimum which then gives 2.33/18 of full "range" = 12.9% full, which would give approx. 97 miles between regens.

49.04g of Oil Ash Residue apparently equates to ~44.5% full/lifetime

That's correct.

I guess if I'm 44.5% through the lifetime of the DPF (given 70k miles) that's probably fine.

Normal for 70 kmiles - oil ash residue is just a calculated estimate.

 

[Cuiken]

@mmi, Just to say thanks for that incredibly helpful post. Really apprecite you taking the time to think about it in proper detail.

Cheers, Cuiken

 

[T6 Syd]

Disagree but agree with mmi

The app calculates the % full based on 24g being full (100%). It doesn't claim to represent the % of 'usable range' used. I think mmi is saying that the app is calculating the wrong thing, not that the app calculation being performed is incorrect.

mmi's method, taken together with the miles driven since regen, does give an easier way of predicting when, in miles driven, the next regen will occur. However, that extrapolation relies on the driving conditions remaining the same, or average, over the whole period. As mmi alludes to, it would also have to use the starting value of what the soot dropped to on each cycle as if it simply assumed a starting point of 6g there would likely be an error, albeit a small one.

The app shows a larger % throughout the interval between regens than mmi's method would but, subject to the correct start value being used, they reach 100% at the same time.

I haven't checked my % ash residue lately, but from memory mine is at around 65% + with 113k on the clock.

 

[WinFreak]

Have a good look at the % while on a long drive, on mine it would start at 6g and gradually go up like normal until maybe 15g and then jump to 24 all of a sudden and start doing the regen, seemingly finishing it all off properly back down at 6g again and then repeating this over and over every 50 miles or so.

This distance got less and less long before we replaced the turbos and dpf and cat and now it does 6g to 24g normally in 150-200 miles.

 

[Cuiken]

Have a good look at the % while on a long drive, on mine it would start at 6g and gradually go up like normal until maybe 15g and then jump to 24 all of a sudden and start doing the regen, seemingly finishing it all off properly back down at 6g again and then repeating this over and over every 50 miles or so.

This distance got less and less long before we replaced the turbos and dpf and cat and now it does 6g to 24g normally in 150-200 miles.

Useful, thanks. I'll check that out.

I really don't like the sound of a turbo, dpf, cat combination failure......