I've been using my VAG DPF for 6 ish years now, really to keep an eye on the oil ash residue.

Three things I'm not sure on - what is the ultimate limit of the oil ash as there seems to be no definitive figure. I'm measuring in (l), which I might guess is litres?

 

The other two things are "differential pressure", which I guess is measured on the inlet and outlet of the DPF? 

 

The third thing is "High Press. EGR Closing (%)" Obviously it is to do with the EGR operating condition - what does it actually show? Does it show the actual degree of movement, and the frequency of operation? Mine goes up and down like a yo-yo and looks impressive - but does/can it give a warning of EGR clogging?

 

Answers on a postcard welcome 😉 

Try tapping on Ash, mine shows as amount and percentage.

 

 

 

Edited 30 November, 20223 yr by Urrell

Hi Yety

 

I would expect the (calculated) oil ash residue to be in grams or percent.  There is a maximum limit, I don't know the exact figure for the Yeti but something like 100 grams.

 

The differential pressure is as you would expect, the difference between absolute input and absolute output pressure.  The bigger the pressure difference for a given mass air flow, the more restrictive the DPF. Presumably there is a threshold which triggers a regeneration.

 

I have no information on the high pressure loop EGR except that it is mainly used at lower speeds and engine loads, with the low pressure loop EGR used at higher speeds and loads.  The latter is fed post catalyst so is less inclined to carbon fouling.

PD would measure oil ash in litres (not literal litres of oil though!)

CR measure it in grams, limits are 80g or 100g etc (does depend on what is fitted to that model car)

see edit below

 

As mentioned by many, there is a % lifespan displayed.  Also note that this has and always will be an estimation as this cannot be measured.  A car that drinks excess oil, will still show the same value, but in reality the physical oil ash will be higher.

 

 

The pressure sensor should be measuring the pressure before the DPF, the 2nd 'port' on the DPF sensor can be connected after DPF or to atmosphere.

 

EDIT: You can use these as a rough conversion of the two measures.

 

PD engines
Generally expect to see 0.5 grams Ash per 1000 miles driven

 

Common rail 2.0 engines
Generally expect to see 1 ml per 1000 miles driven

Edited 30 November, 20223 yr by varooom

14 hours ago, varooom said:

CR measure it in grams, limits are 80g or 100g etc (does depend on what is fitted to that model car)

My CR EA189 engine measures oil ash in litres with no percentage, the reading  presently on 0.18 after 166000 miles

Bit annoying really as no one knows the limit!

50 minutes ago, idleness said:

My CR EA189 engine measures oil ash in litres with no percentage, the reading  presently on 0.18 after 166000 miles

Bit annoying really as no one knows the limit!

Only VAG know the limits, and they don't exactly advertise this amount.

There is a test plan you can run in ODIS to check the lifespan, but I don't think it answers back a percentage either.

 

Today I will look at my own car and check again at some point.

17 hours ago, Urrell said:

Try tapping on Ash, mine shows as amount and percentage.

 

 

 

Thanks, tried that and the screen box only darkens and I think stops that box from reading.

 

I emailed the guy ages ago 05/2018:

"I've got a CFHF engine, not listed in the App, so I choose engine to be specified "read from ECU".

I haven't direct experience with CFHF engine and no reports from users. But the app works with CFHA, CFHC and CFHD that are very similar engines, probably the only difference is the power as usually vag do changing the last character of recent four characters engine codes.

So probably your engine will work using the engine group 3 (you should se it manually into options menu because the app doesn't know your engine code yet), but I can't be sure 100%. You should try with free app and with a good adapter.
 

Bye, Daaren"

 

OK, so it's possible no-one knows what the upper ash limit is, I guess it depends on driving style/ use and so many variables that only time will tell.

 

It's the EGR one that bugs me, what is it actually showing, the  phraseology is difficult to interpretate?

2 hours ago, Yety said:

It's the EGR one that bugs me, what is it actually showing, the  phraseology is difficult to interpretate?

I read it as when it shows 100% it's closed, normally during hard acceleration and when doing a regen.  The rest of the times it's various states of closed i.e. when it shows 16% it's 16% closed or 84% open.

 

I may of course be completely wrong.

Hi

 

From what I have been able to ascertain, ash in a DPF has a packing density of roughly 0.4 grams per cubic centimetre, which equates to 400 grams per litre or 72 grams for 0.18 litres. 

 

Unlike soot, ash cannot be removed by oxidation during a regen i.e. it's the residue that gets left behind

 

I have no idea what algorithm VAG use to calculate the ash volume, and in any case this calculation is only a guide to what's really happening.

Using the picture above 26% =17.91g so 100% would be (17.91/26) x 100 =68.88g

And if your figures are correct at 72g my DPF is over full. 😱

I'm getting shorter distances between regens down to 89miles sometimes 😟

My local indy and local DPF specialist says leave it until it no longer regens before looking at it.

 

ETA someone on here had an ash figure of 2.x on VAGDPF ......

Edited 2 December, 20223 yr by idleness

With the right tools you can find out your max oil ash value yourself.

 

 

Apart from the full figure 80g that's similar info to VAGDPF.

Multiplying up your ash vol/mass figures I get 78g for mine 

So whether its 72 or 78  its getting close to the 80g full mark.

Assuming 80g is the Yeti dpf full figure..

Don't know where this came from - I saved it in 2018!

It's from this document, it had been cut off the bottom the source.

 

 

 

Hi

 

Those graphs from VTP-122 are for soot (carbon) load.  The soot load goes down during regeneration as the carbon particles are oxidised (= burnt).

 

The ash stays behind

Hi I have the same problem what should I do skoda fabia 1.6tdi 2010 cayc engine

7 minutes ago, coley8978 said:

Hi I have the same problem what should I do skoda fabia 1.6tdi 2010 cayc engine

I think you may wish to expand upon what problem you are having, lacking details.

 

Excess soot?

Full DPF oil ash?

Regens happening all the time?

Sorry the problem I have is my skoda fabia 1.6tdi cayc engine has a dpf problem it says when scanned that dpf filter High at I have also noticed the the engine never gets to operating  temp have changed water pump and thermostat  expansion  bottle and cap anybody got any idea what's going on 

Where in Leeds can I buy vcds

4 hours ago, coley8978 said:

Where in Leeds can I buy vcds

Well, there's this thing called the Internet...  

8 hours ago, coley8978 said:

Where in Leeds can I buy vcds

You have a PM, I can scan the car if you like and see if I can get to the bottom of it all.

Short term relief can be obtained by squirting in DPF cleaner spray through the sensor hole, I've done this a good number of times since the summer, the effect is cumulative in that the first one/two cans make no difference but keep plugging away. 

 

It's never solve this issue in the same way as a new DPF, but at £10 a can and 15 mins of your time it's worth a squirt, as they say.

Hi I would for you to scan it but I don't know how to pm you sorry

1 minute ago, coley8978 said:

Hi I would for you to scan it but I don't know how to pm you sorry

Look at top of the webpage, top right (on desktop PC) for the envelope icon.

You can open and reply there

 

https://www.briskoda.net/forums/messenger/