[TurboABA]

Thanks TurboABA.
Yes, did note some of the other threads around, especially 2 liter diesel, but keen on Touareg specifics, given its clubtouareg it makes it relevant for me atleast.

Not intending to move or change my commute but trying to understand tech as best.

I'm simply telling you that it's out of your control my friend. All you can do is keep everything in as good of a functioning state as possible and see how that works for you. The more you dig, the more you'll see all the various results from everyone attempting to come up with a pattern or accurate formula..... Even finding the exact ash level limit will be difficult.

But keep us posted

 

[Singh]

Thanks TurboABA.
Yes, did note some of the other threads around, especially 2 liter diesel, but keen on Touareg specifics, given its clubtouareg it makes it relevant for me atleast.

Not intending to move or change my commute but trying to understand tech as best.

I'm simply telling you that it's out of your control my friend. All you can do is keep everything in as good of a functioning state as possible and see how that works for you. The more you dig, the more you'll see all the various results from everyone attempting to come up with a pattern or accurate formula..... Even finding the exact ash level limit will be difficult.

But keep us posted

Thank you sir, appreciate your guidance

 

[Singh]

Here's some interesting observations and readings from the DPF covering weeks of city driving, build up of soot, going for a drive up the coast on the freeway at 110kmph where a regen occurred, and back - 140km return weekend trip we do every now and then.

Between the first and second reading it was 12days of city stop start driving. You can see how it builds up. And then how quickly a quick 20min freeway run at 110kmph triggers a regen and burns the soot off.
And even though you are doing a freeway run it starts to build up again to where it was two weeks ago when I hadnt done any freeway driving for months.
Ash levels have remained the same ie 0.04l

1st reading ever taken of DPF, reflecting atleast 3 months of NO freeway driving but city stop start work commute:
Particle filter: time since last regeneration 4083 s
Particle filter: soot mass calculated 11.50 g
Particle filter: soot mass measured 3.08 g

2nd reading taken earlier this morning before heading out for coastal trip(70kms), 95% freeway run at 110km:
Particle filter: time since last regeneration 40855 s
Particle filter: soot mass calculated 34.93 g
Particle filter: soot mass measured 16.68 g

3rd reading take enroute, about 25mins into the trip, on the freeway at 110kms when a regen had just taken place. Laptop was hooked up all the way:
Particle filter: time since last regeneration 60 s
Particle filter: soot mass calculated 6.82 g
Particle filter: soot mass measured 3.89 g

4th reading taken after the trip, total 150kms, 95% freeway driving at 110km:
Particle filter: time since last regeneration 6892 s
Particle filter: soot mass calculated 10.74 g
Particle filter: soot mass measured 2.91 g

what does this establish?
- freeway runs help regen for sure. within 25mins the systems does a burn off and brings levels down dramatically.
- but regen occurs in city traffic just as the same and brings soot levels to the same as freeway runs.
- after a good freeway run and a regen, my dpf soot level has built up and is around the same I had when I had done only months of city stop start driving.

I am thinking maybe a freeway run is really not necessary, as long as there is a regen occurring during the city traffic, which it seems be doing for me. Its about a 30km daily return trip for me in city stop/start traffic btw.

 

[TurboABA]

Bro, quit stressing..... you don't need to worry as long as the systems works and you don't have any messed up sensors.
There are PASSIVE regens (read, accumulated soot burns off automatically from the system heating up based on engine load\operating conditions)
There are ACTIVE regens (read, the system triggers a regen and changes various parameters to induce heat into the system)

I don't know for sure if it's the same on the 3L as on my 2L, but just as an added note, on my 2L, a regen is "pre-programmed" to happen every 700km or so regardless of conditions, just to "cleanse the system". I suspect that the 3L doesn't do this since it uses the AdBlue unlike my 2L which does not.

Regarding seeing changes in your ASH levels.... you will have to drive like 20k or so to see changes.... the ASH level doesn't increase that fast. I'd have to dig up one of my old 2L threads where I was keeping track of it to give you a better idea of the timeline\milage it takes to actually notice a value change.....

Also note that your most "active" soot value, is CALCULATED..... that's basically the system using an educated guess to say that it "should have" generated X amount of soot since the last regen, based on operating conditions, loads, parameters, etc. Your MEASURED soot is much lower because it's actually determined by a flow reduction and differential pressure measurements before\after the DPF, etc. This also serves as "proof" of the above mentioned PASSIVE regens which take place "naturally".......

The last thing is, that even your ASH load, is also only a "best calculated guess" by the system.... I am willing to get that if both you and I could keep our vehicles running to the point of fully maxing out our DPFs ASH levels "physically", we would max out (clog up) at different values.

 

[TurboABA]

Here's an extract from my 2L post on a different forum where I dealt with all these regen issues on my 2L as previously mentioned.
This should help give you a better idea of what to expect in terms of how fast you'll see your ASH load change, etc. Hope it helps.

Just I had suspected, and as I have been noticing from monitoring my SGII, my new driving routine and conditions are causing active regens at a much more accelerated rate. Here's a quick breakdown of how I've accumulated my ash volume since I've purchased the car.

The initial ~115,000 kms of long, non-grid lock commuting resulted in 69ml worth of accumulation.

The following ~10,000 kms of same condition driving are unaccounted for since regens were not happening, and whatever ash resulted from me forcing the system to regen once I replaced my sensor remains an unknown.

The following ~35,000 kms of slightly less "optimal" driving conditions resulted in an additional 9ml of accumulation.

My last ~2,000 kms of crap short commutes/daily use in stop-and-go (at times) conditions, have resulted in an additional 9ml of accumulation.

As I had mentioned before, my new commute consists of a short 11min/13km drive where the car doesn't even reach full operating temperature in the mornings, on the way to work. The return trip is much worse, as it usually results in a 25-30min commute due to traffic and grid-lock. This is compared to the prior driving pattern of 44min/53km each way, with very little traffic.

So just a heads up to all who are following the "milage vs ashloads" threads...... it's not as simple as that.... driving conditions and use patterns are much more important than milage alone.

I have see a very significant increase in both my active regens as well as my fuel consumption as a result of the above.

 

[Singh]

Great, thanks.

Dont want to be stuck outback in limp mode thousands of kms away from a dealer.

So very keen on understanding the technical details of how it all works

 

[TurboABA]

Great, thanks.

Dont want to be stuck outback in limp mode thousands of kms away from a dealer.

So very keen on understanding the technical details of how it all works

I hear you..... but based on my experience, you have plenty of time if you actually want to address an issue once you throw a code. I just choose to be ignorant in my case with my 2L (which is probably what a lot of people do) and then had to learn the hard way about how the system works etc in order to bring it back from the dead. If I would've addressed my initial problem (an EGT sensor) in a timely manner, I would've saved myself a wackload of headaches and such.

On a sidenote, my Jetta ran fine the whole time without regens, and there was no performance loss or degradation in MPGs or anything. So based on that alone, I would say the system is fairly forgiving and doesn't actually leave you stranded.... you're presented with plenty of time to address the issue unless it's something critical which is when it goes into LIMP mode to save you from yourself.

This is obviously my experience.... results may vary

 

[Singh]

Its the varying results that got me thinking and delve deeper into this.

I will run a scan on my mates V6 tdi to see what levels and contributing factors come to light.

If 500-600kms of freeway driving at over 100kmph wont help to do a regen when the soot levels were so high & building (assuming) and instead put the car in limp mode then there's no choice but take it to dealership.
Luckily for him there was a dealer closeby but closed for the day, so had to book in to a motel overnight and get a controlled burn carried out at the dealership next day.

Again, wouldnt it be great to have a visual aid/reading that shows you the soot levels and imminent regen so one could take certain actions accordingly.
Perhaps the same way we see oil and coolant temps go up and managed by the system but if not then can do something about it.....

 

[IBrad]

I looked into getting my dpfs cleaned a year or so ago. 130,000km on the clock.

my interest was piqued when service company said dpf change at 140k service at a cost of $4k each plus labour.
said I will wait until the light comes on.

spoke to two companies, one in Sydney, one in Brisbane, both specialise in cleaning truck dpfs.
before cleaning, they do a flow test and measure differential pressure across the dpf.

then do the same after cleaning, which gives a clear indication of how well it has worked.
cleaning from memory was a combination of chemicals / heat and pressure.

both guys I spoke to asked the same question. what do you do with the vehicle.

tow a heavy boat a long way, or long highway driving, mostly.

both said come and talk to us at 180k - 200k, not before as the exhaust temps will be hot enough for soot / ash not to be an issue.

one of them gave me a very detailed explanation of how the VW DPF system functioned, (most of which has been covered in this thread) which I took notes on and now cant find...
cleaning wont put them back to new, but if you get another 100k out of them, it would be worth it.

in terms of doing this, $600 roughly each. the dpf regen will be max 600oc, more likely 450oc due to the eoly$ additive. low carbon steel doesn't melt until around 1450oc, so rewelding dpf wont be an issue.

I plan to go down this path when the time comes, a 2nd life on the dpf's will just about see the car out.

worst case, I blow $1200 and then have to buy new dpf's.

 

[TurboABA]

Sighn,
There isn't very much you can do as a driver to address anything. The system is complex and automated, and the engine is so efficient, that even the manual suggested "HWY drive" doesn't load it up to the point where the DPF will get hot enough to do a full regen. Once again, during my self-induced issues on my 2L, I tried all of the "drive hard", "long drive", "elevated RPMs", etc. scenarios suggested by user manuals and other forum members without any first hand experience while monitoring the EGTs and before\after DPF temps. No matter what I did, I couldn't create the required amount of heat in the system. (also note, that on my 2L, the DPF is right after the turbo, so exposed to even more heat.... whereas in the 3L, it's way downstream and FAR AWAY from the turbo...... *read* you will NEVER create the required heat by just driving hard.... maybe if you're towing at max capacity, uphill, in 40deg C ambient heat, and at 3k RPM)

The indicators you wish for would only stress drivers out. When all is well, regens are triggered when required and when all pre-requisite conditions are met. As stated before, you can add something like a ScanGuage to monitor various sensors and EGTs if you really wish to keep an eye on things.

Regarding your friend's experience, I would suspect that he has\had some other lurking issue which was preventing the system from meeting the pre-requisite parameters and that's why it couldn't trigger a regen. Once again, the system takes input\readings from something like 27 different sensors (EGTs, pressure, MAF, various other system temps such as coolant, oil, voltage readings, etc.) to ensure that it can safely perform and sustain a regen. If a regen is in process and is interrupted (you park the car), it will either continue it for up to 10-15min if it determines its safe to do so, or it will shut it down and re-attempt it on next drive once all parameters are met. There are very few scenarios, under which repeated multiple short drives can impede the system from doing it's job, and these types of scenarios are when you would require a "service regen".... otherwise, you will only end up in this sort of situation if you have one of the aforementioned 27 (or whatever) system components not functioning properly. In the 2L, it can be as simple as a stuck exhaust flap that would cause this scenario.


IBrad,
These DPFs are very different than the heavy truck DPFs which can be serviced by some of the shops you've mentioned. I've seen very few attempts of "cleaning" a VW DPF which were successful and actually allowed the user to get say another 50-100k out of the system. If you know of any such documented success stories, please enlighten us. The VW DPFs are very compact and "fragile" for a lack of a better word in comparison to the trucking industry units that get "power washed", cut apart and "gutted", etc.

 

[TurboABA]

If 500-600kms of freeway driving at over 100kmph wont help to do a regen when the soot levels were so high & building (assuming) and instead put the car in limp mode then there's no choice but take it to dealership.

Here's some info for ya.....

 

[Singh]

If 500-600kms of freeway driving at over 100kmph wont help to do a regen when the soot levels were so high & building (assuming) and instead put the car in limp mode then there's no choice but take it to dealership.

Here's some info for ya.....

Thanks TurboABA
Does active regen leave the dpf worse off in terms of longevity?

 

[TurboABA]

Thanks TurboABA
Does active regen leave the dpf worse off in terms of longevity?

Theoretically, I believe so. I would also suspect that "service regen" is even more damaging to it as it creates even hotter burning conditions in order to incinerate the "restrictions" and it is performed with a stationary vehicle. I would imagine that during both a passive and active regen, with the vehicle being in use, some of the resulting heat is much more effectively dissipated from the system and is thus less damaging to all components involved.

 

[Singh]

That diy video you posted, that be considered an active regen then?
That is pretty much mimicking what a dealer would do?

 

[TurboABA]

That diy video you posted, that be considered an active regen then?
That is pretty much mimicking what a dealer would do?

That's a "service regen"....... an active regen is what the system does when operating normally during your drive when all prerequisites have been met. From my perspective, the video procedure should only be done if a failure has resulted in the cycle of regens being interrupted and you are presented with the MIL about he DPF and\or "Engine malfunction - workshop" warning.

 

[Singh]

What I meant is that a service regen ie the video is similar to active regen when the ecu forces a regen by heating it all upto 650degrees.
Active regen will be triggered by ecu when passive regen hasn’t been achieved due to city driving conditions ie not enough heat and exhaust pressure like on the highway.

So could we say the difference between active and service regen is that the latter is triggered manually? Knowing that there is a soot limit which once reached will put car in limp mode and disable active regen.

 

[Odessa]

Um .. am i seeing a new breed of treg owner (with more exposure and expertise) come into the forum recently. I do apologize i have been away for many months given the loss of the last pony and only now being able gain momentum again.


Well done on this thread Singh really good for the long term-ers amongst us

 

[Singh]

Um .. am i seeing a new breed of treg owner (with more exposure and expertise) come into the forum recently. I do apologize i have been away for many months given the loss of the last pony and only now being able gain momentum again.


Well done on this thread Singh really good for the long term-ers amongst us

Hi Odessa,
we're all learning, or atleast I am

Sorry about the Pony, what happened?

 

[TurboABA]

So could we say the difference between active and service regen is that the latter is triggered manually?

In a very simple way, correct.
But keep in mind the following:
Passive regens happen at 500deg C
Active regens happen at 650deg C while the vehicle is moving, airflow all around it and under it, through radiators, etc......
Service regens happen at 650deg C wihtout any additional airflow.... just sitting still "trying to start itself on fire"

I know which scenario I'd prefer for my own vehicle.

In my Jetta, since I have the ability to take EGT readings front the sensor right after the turbo, I see temps of 800deg C during an active regen...... for periods of up to 15min or so.
This tells me that my turbo is probably seeing close to 900deg C during the same time...... not ideal for turbo life at all.

 

[Odessa]

Wow thanks ABBA .... TuurboBABDABDA ... hmm fat fingers!! .... you seem to have a massive wealth of knowledge you are keen to pool into the community I for one am very appreciative of the extra knowledge thankyou ... is ther somewhere this comes from other that personal exposure ?