Monitoring DPF with VAG DPF App.

[Yetiflute]

I bought the fascinating VAG DPF Android app two weeks ago and have had it connected to car all the time since then and have monitored the DPF behaviour on my car.  It is a facelift Yeti  150ps Monte Carlo with 120080 miles at the time of the regeneration described below. I though some technophobes might like the results.

 

I started monitoring at 11904 miles with a calculated soot mass of 11.75 grams and oil ash residue of 5 grams and with a distance of 80 miles indicated since last regeneration and an indicated 49% until the next regeneration due at 100% (I discovered)

 

I obtained a screen shot only 1 mile before it started its regeneration (at 12080 miles) with the figures 23.87 grams soot mass. 254 miles since last regeneration, 5 gm ash, and driving time since last regeneration 609 minutes. Immediately after that screen shot the app boinged at me and the regeneration started. Soot mass was just over 24gm. I witnessed dpf temperatures up to 700 degrees max but mainly fluctuating from about 550 to 660 degrees and the soot mass level gradually fell. The regeneration duration was 20 minutes and about 8 miles. There were two stops at traffic lights during the process.

 

I stopped the car 1 mile after it finished and did another screenshot which showed the results 12089 miles (so about 8 miles driven), 5.63 grams soot mass, 5.1 gram ash residue and 23% indicated till next regen (at 100%)

 

The above was an auto active regen (not a forced one due to any warning light). Before this regeneration occurred I did some aggressive high rev driving on a clear dual carriageway and the app went boing and indicated a regeneration. The DPF temperature had reached 375 degrees. This regeneration ceased as soon as I slowed down to normal driving with the dpf temperature dropping. This exercise convinced me that on a long run there would not normally be any passive regeneration unless one drove quite aggressively at high revs/ high speeds - much more so that normal motorway driving in 5th or 6th gear.

 

All the soot mass figures were the indicated calculated ones which are obviously what the car ecu uses. The measured soot mass bears no resemblance ending up with negative values even. Again I understand this to be normal.

 

I drive mostly short journeys now.

 

From what little I have read I think my experiences above show a normal healthy dpf.

 

Sorry about this long speel but hopefully of minor interest to some

[Urrell]

The screenshots uploaded would be nice.
What's the oil ash reading as G and %?
This is mine at about 26,000 miles.
 

 

Edited 7 May, 2018 by Urrell

[Yetiflute]

I’m not sure how to export the screenshots off my old Samsung phone now unused except for this app. At 12091 miles the oil ash Reading is 5.1gm and 6%.

The oil ash went up from 5gm to 5.1gm before/after regeneration

[Urrell]

11 minutes ago, Yetiflute said:

I’m not sure how to export the screenshots off my old Samsung phone now unused except for this app. At 12091 miles the oil ash Reading is 5.1gm and 6%.

The oil ash went up from 5gm to 5.1gm before/after regeneration

 

Ah, I thought oil ash residue was low for 120080 miles in the first post..

[Yetiflute]

5 minutes ago, Urrell said:

 

Ah, I thought oil ash residue was low for 120080 miles in the first post..

 

I think it relates well to your results with your mileage being double mine

[Urrell]

1 minute ago, Yetiflute said:

 

I think it relates well to your results with your mileage being double mine

Read the mileage you have put in your 1st post, nearly 5 times mine.

[Yetiflute]

17 minutes ago, Urrell said:

Read the mileage you have put in your 1st post, nearly 5 times mine.

Whoops, too many zeros- won’t let me edit now either !!

[Yetiflute]

1 hour ago, Yetiflute said:

 It is a facelift Yeti  150ps Monte Carlo with 120080 miles at the time of the regeneration described below. I though some technophobes might like the results.

Sorry for confusion. Above mileage should read 12080

[Yety]

I've got a slight problem - and I've never got to the bottom of it.

 

The Oil Ash Residue box has (gm) as measurement when not initialised, then it turns to (0.8 (I) when ignition on and engine running.

 

Gm I can understand, but what unit is (I) ? It's recently gone up from 0.07 (I) at 87k+.

 

Has anyone an answer as to either why, or how I can get it to read gm?. What is the limit on oil ash residue - in something

[Urrell]

59 minutes ago, Yety said:

 What is the limit on oil ash residue - in something

 

Do you not have it as a percentage in white like mine reading 13% above?

[Yetiflute]

1 hour ago, Yety said:

Has anyone an answer as to either why, or how I can get it to read gm?. What is the limit on oil ash residue - in something

 

No idea why your app does what you say. I have found something quoted in a VW forum - I cannot verify the absolute truth of this statement but seems to give you a conversion factor :-

 

DPF needs replaced when the volume = 45 grams (380 ml

[Urrell]

1 hour ago, Yetiflute said:

DPF needs replaced when the volume = 45 grams (380 ml

A VAG independent near me say they can take the DPF off to chemically clean it at 80,000 miles for about £300.
I wonder what VAG-DPF would show after that.

[Yetiflute]

36 minutes ago, Urrell said:

A VAG independent near me say they can take the DPF off to chemically clean it at 80,000 miles for about £300.
I wonder what VAG-DPF would show after that.

A good thing about having the VAG-DPF app is that at say 80000 miles you could make a judgement as to whether that act was worthwhile at that stage. Very useful to be able to properly monitor it so easily.

[langers2k]

2 hours ago, Yetiflute said:

No idea why your app does what you say. I have found something quoted in a VW forum - I cannot verify the absolute truth of this statement but seems to give you a conversion factor :-

 

DPF needs replaced when the volume = 45 grams (380 ml

 

Can you add a link to the post in question?

 

The only 'maximum ml' figure I've seen mentioned is 175ml although people have reported hitting 250-300ml so I'm curious where 380ml came from

 

 

Looking at the screenshot from Urrel, the app suggests the maximum is ~72g (based on 9.36g being 13%) and therefor the lifetime could be 200,000 miles for their DPF.

[Yetiflute]

The link to the post I saw is https://www.golfmk7.com/forums/showthread.php?t=19044&page=2

 

it is in a post made by zg3409

[langers2k]

Cool, so zg3409 quoted MacBuckeye who is half right.

 

If the soot mass is above 45g then it's no longer safe to regenerate so the DPF needs replacing. If the system is working correctly or warning lights are dealt with in a timely matter, this shoud not happen. This is mentioned in various VW literature. I've no idea where either got the 45g equals 380ml from so I'd ignore that unless it's verified elsewhere. 

 

In normal use, its the oil ash volume that will determin the lifetime of a DPF. I've not seen any maximum mentioned in VW literature.

 

The figure 175ml has been mentioned a few times but it'll depend on the engine code as to how it reports oil ash (g or ml). At least for Urrel, the DPF app suggest a max of 72g for the CAYC.

[Yety]

4 hours ago, Urrell said:

 

Do you not have it as a percentage in white like mine reading 13% above?

 

 

No . Possibly because my engine type is not on the app's list - CFHF, which is strange as a CR 110 bog standard diesel.

 

Still no definitive oil ash limit then.

[langers2k]

18 minutes ago, Yety said:

No . Possibly because my engine type is not on the app's list - CFHF, which is strange as a CR 110 bog standard diesel.

 

Still no definitive oil ash limit then.

 

At a guess, it'll be 175ml but that's just based on general wisdom rather than anything solid.

 

On my CFHC (2.0 140ps), the oil ash is also shown in l (litres), I don't record it often but I have two figures:

- 82,000 miles showed 0.06l

- 137,000 miles showed 0.1l

 

Assuming the above is the maximum, I might get 240,000 miles (386,000 km) from the DPF. Your reading of 0.07l in 87k isn't too different from mine so it's probably normal.

[pinkpanther]

1 hour ago, langers2k said:

 

At a guess, it'll be 175ml but that's just based on general wisdom rather than anything solid.

 

On my CFHC (2.0 140ps), the oil ash is also shown in l (litres), I don't record it often but I have two figures:

- 82,000 miles showed 0.06l

- 137,000 miles showed 0.1l

 

Assuming the above is the maximum, I might get 240,000 miles (386,000 km) from the DPF. Your reading of 0.07l in 87k isn't too different from mine so it's probably normal.

Only 3 data points for me thus far (2014 140 BHP), but seems to be rising in a linear fashion.

 

Assuming a max of 0.18l (175 ml) I'd be looking at DPF replacement around 120k miles / October 2020.

 

More here: https://www.briskoda.net/forums/topic/443518-vag-dpf-app/?do=findComment&comment=4995856

Edited 7 May, 2018 by pinkpanther

[pinkpanther]

4 hours ago, Urrell said:

A VAG independent near me say they can take the DPF off to chemically clean it at 80,000 miles for about £300.
I wonder what VAG-DPF would show after that.

Given the data VAG DPF works with is all assumed, rather than actually measured by the ECU, I guess VCDS would be needed to tell the ECU the DPF had been cleaned?

 

Otherwise I'd guess the ECU would continue to assume the DPF was continuing to fill?

[Urrell]

2 minutes ago, pinkpanther said:

Given the data VAG DPF works with is all assumed, rather than actually measured by the ECU, I guess VCDS would be needed to tell the ECU the DPF had been cleaned?

Pressure differential between inlet and outlet?

 

[pinkpanther]

2 minutes ago, Urrell said:

Pressure differential between inlet and outlet?

 

The differential pressure across the DPF would certainly alter (reduce) following a cleaning process, but I'd assumed the oil ash residue level would require resetting?

 

My understanding is the end-of-life of the DPF is dictated by it reaching a certain oil ash residue level (? 0.18 l).

 

I assume a cleaning process would presumably wash this out, but the car's ECU would then need to be told this had happened.

 

[pinkpanther]

Of note I'm now at 68k miles and the oil ash residue remains 0.07 (40%).

 

It only seems to jump up in steps of 5-6k miles, so expecting another jump around 70k miles.

[Yety]

Thanks to all, I guess my unit of oil ash is litres, and there are some sort of estimate as to ultimate final weight/volume floating about.

 

I guess the whole subject is based on a linear progression, the algorithms used in the ECU and the app etc, etc. Our intention when buying the Yeti was to keep it for 10 years without major expense - which looks probable. Our previous Rover 25 diesel was faultless over the ten years ownership, but much less complicated, more old school diesel lugging.

[ejstubbs]

12 hours ago, pinkpanther said:

Given the data VAG DPF works with is all assumed, rather than actually measured by the ECU, I guess VCDS would be needed to tell the ECU the DPF had been cleaned?

 

Otherwise I'd guess the ECU would continue to assume the DPF was continuing to fill?

 

Same process as would be followed if the DPF had to be replaced, perhaps?