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Obviously a lot of people are driving Touaregs and other VW cars in city traffic, and generally none of them have problems with DPF regeneration. This particular car most likely had something other wrong with it, and that was what possibly caused the DPF problem - if it was a DPF problem in the first place.

As for the DPF cleaning: the general consensus about this is, that most non-invasive DPF cleaning methods (that somehow flush the filter with some fluid) do not really work, and even though they might remove some of the ash, they will definitely not regenerate to the filter to anywhere new level. They might help get rid of the DPF warning for a while, but in the long term they're not only not a solution, but cost more than buying a new filter in the first place.

There's also another method of DPF "cleaning", where they open up the filter housing, and actually replace the filter elements in it, then wield back the housing. This method theoretically resets the DPF capacity to original, but also has its own problems. The most prominent ones are that the new filter elements might not fit the housing perfectly, and thus the exhaust can blow by the filter, defeating its purpose. The other problem is that the DPF gets extremely hot, and the new welds might not be able to withstand this temperature. This will obviously result in a very dangerous situation, where the car can burn down during a regeneration attempt.

All in all, the only real and reliable solution to "clean" the DPF is to replace it with a completely new one. Now, obviously VW will charge a small fortune for a new filter, but there are reputable 3rd parties that supply perfectly fine and reliable new filters, which can be purchased at reasonable prices. In the end DPF is just another "wear" item in a car, that has to be renewed every once in a while - even though with most cars that's just once (or two at most) in the lifetime of the vehicle.

However, your complaint on there being no indication of the DPF generation being in progress is valid, and it would be useful in many ways - even if that's not helping to avoid interruption of the process, because as said, in the end that doesn't matter much, and generally does not cause any problems whatsoever, unless there's something else wrong with the car. But if there would be such an indication, and the driver could see it start happening more often then usual, it could possibly help catch a lot of other problems early, like injector, air intake or boost problems, which all increase the amount of soot generated and thus also the frequency of DPF regenerations.


It is beyond me why VW decided not to provide _any_ feedback on DPF regeneration visible to the driver - but I'm pretty sure they had a very good business reason to do so. Like saving 50 cents in manufacturing costs of a car with a sticker price of $70.000+.
 

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Good point well made.
 

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Discussion Starter #23
Wonder if these dof values can be shown in the nav screen- even in the green screen, or with an obd bluetooth connector thingys
 

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Wonder if these dof values can be shown in the nav screen- even in the green screen, or with an obd bluetooth connector thingys
I'm not sure about the generic OBD2 readers, but with one that can read the VAG-COM measuring blocks and transfer that somehow to the screen you definitely can, because load values, DPF regeneration status, and even things like distance and total fuel consumption since last regeneration are stored and easily readable through the appropriate MVBs. What exact blocks you've to read depends on the actual engine code though.

Original RNS units are at disadvantage here, but Android based ones that can run apps like Torque should have it very easy. That said I even saw custom circuitry built that could not only display numeric data, but even graphs of MVBs over time on those small red-colored MFDs in Golfs and such (which I think worked used standard CAN-bus packets) - so, its technically definitely doable. But I'm not aware of such solutions being sold for Touaregs.
 

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Discussion Starter #25
I had a quick look at the green screen, and I can see scan results and errors across all modules can be displayed- one doesn’t even need vcds to run a scan to see any errors- just use your green screen menu!
Dpf fault and error will show here so that’s a good thing, but would be good to get an ongoing reading rather than waiting for when its too late
 

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The following is my gathered knowledge from 1st hand experience, on my 2L TDI Jetta (2010, owned since new).
The DPF system is very similar to the 3L on my 2014 Treg, and I can only assume that it functions very similarly.

Since I've been the one and only driver, I have driven (and still do) all of the 248k+ kms on it, in various conditions and driving\commuting styles, and have monitored things over time. During the past 9 years, I have changed jobs and residences a few times, so my driving patterns have varied from long 50kms each way, trafficless commutes, to 13km each way, stop-and-go ones, to anything in between.

Regardless, based on my experience, the system is quite complex and takes a lot of reading from all sorts of sensors, etc. It has fail safes built in, and although it is stated all over the place that you must replace the DPF if you exceed a certain amount of soot, etc., I can tell you that if you force a system regen using some common sense once you've reached those limits, you can avoid burning your vehicle down, etc. I exceeded those limits over 125k+ kms ago, and I did what everyone and everything told me not to do (forced a regen) and my system/car still functions and drives 4 years later, etc.

Ofcourse, there's a physical limit to how much ASH the system can store in terms of volume, so yes, it has a limited life.
Lastly, you guys need to realize that there's no real reference milage/value that you can go by in terms of other user's experience. The actual driving patterns\styles\conditions of each vehicle will generate different amounts of soot\regens\ash over the same milage. As stated above, I've seen these exact changes in my 2L over the last 9 years of monitoring it.
 

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Discussion Starter #27
Thanks for sharing the experience.
Have you ever noticed regen occurring?
 

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It is beyond me why VW decided not to provide _any_ feedback on DPF regeneration visible to the driver - but I'm pretty sure they had a very good business reason to do so. Like saving 50 cents in manufacturing costs of a car with a sticker price of $70.000+.
The why not actually seems fairly straightforward to me. VW claims that the regen process should be transparent to the driver/owner, so why present any information that might lead anyone to refute that claim?
 

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Thanks for sharing the experience.
Have you ever noticed regen occurring?
In the Touareg, I can't tell thus far......
In my Jetta, I can easily tell..... by the RPM at idle, by the smell of the exhaust, by the cooling fans going bonkers, by the drop in full tank range.... and I've also added a ScanGaugeII with which I constantly monitor EGTs before the turbo (among many other parameters).....
As of lately, my Jetta is doing regens like it's going out of style (especially after the "fix")
 

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Discussion Starter #30
Thanks for sharing the experience.
Have you ever noticed regen occurring?
In the Touareg, I can't tell thus far......
In my Jetta, I can easily tell..... by the RPM at idle, by the smell of the exhaust, by the cooling fans going bonkers, by the drop in full tank range.... and I've also added a ScanGaugeII with which I constantly monitor EGTs before the turbo (among many other parameters).....
As of lately, my Jetta is doing regens like it's going out of style (especially after the "fix")
Thanks TurboABA
Seems it quite inconspicuous in the Touareg.
I have never been able to tell when its happening, so the vcds doesn’t lie I guess and tells you how many seconds ago a regen was undertaken- refer the picture in the first post.
On my next freeway run i will keep the laptop connected and see if it can be picked up in real time- supported by passenger of course!
 

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Discussion Starter #32

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Discussion Starter #33
If one can manage dpf levels with vcds and do a regen manually whenever soot goes over 28g(city drivers) this begs the question whether there is merit in frequent long trips just to ensure a regen is happening.

I mean which method is better to have lower ash levels overall- manual regen in city driving or automated ecu driven on a high speed run.

Btw, does anyone know what are the exact parameters when the ecu automatically will initiate a regen- what the soot, coolant temp, rpm, speed, etc levels have timo be?
 

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If one can manage dpf levels with vcds and do a regen manually whenever soot goes over 28g(city drivers) this begs the question whether there is merit in frequent long trips just to ensure a regen is happening.
As already explained previously, frequent long trips are absolutely not _necessary_ for an auto regen to happen. Lots of people are driving Touaregs in mostly city traffic, and they have generally no problems with auto regens happening. If they have, then there's something wrong with the car's systems, and it's not working properly for some reason - and that's why the regen is not happening.

That said making a longer trip every once in a while definitely can have it's benefits, but they're definitely not required for the DPF to work as intended and for its regeneration cycles happening. However, it might help with general (de)carbonization of the engine and exhaust components, albeit obviously only to a limited degree.

I mean which method is better to have lower ash levels overall- manual regen in city driving or automated ecu driven on a high speed run.
The best method is to let the ECU to do its job on its own. As long as it can do that, there's no reason to interfere (well, at least not the "hard" way), because you can't possibly know what's working better and more effectively than VW's engineers who spent decades with experimenting and trying to figure out the best and optimal method to manage soot levels. The VCDS method is only there for emergency purposes, when for some reasons the car's systems couldn't do their job - but there's no reason to fall back to emergency regeneration while they are working fine.

Btw, does anyone know what are the exact parameters when the ecu automatically will initiate a regen- what the soot, coolant temp, rpm, speed, etc levels have timo be?
The related Ross-Tech page lists some numbers for the forced regen, and I think it's safe to assume, that the same parameters apply to auto regens. The only distinction between these should be that auto regen is initiated based on the calculated soot level, which in turn is determined by the ECU by measuring the pressure difference between the two ends of the particle filter.
 

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Discussion Starter #35
Thanks Gnits, maketh sense.

Its good to know the parameters to ensure one can assist or make it easier for a regen to occur around town.
I will keep monitoring the levels over the months and compare to those who are mainly using their Touareg for long runs
 

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I believe some of you are somewhat miss-understanding things a little.
Jumping to that conclusion, I will now attempt to give you the Cole's Notes

- Soot is what is generated by the engine, and this amount will vary based on operating conditions. Not all users will generate the same amounts based on their specific conditions, use, operating parameters, system health, driving habits, etc.
- Once a certain level of the above soot accumulated in the DPF, the system recognizes that it needs a regeneration to "clean the DPF".
- When any regen occurs, weather it is passive, active, ECU or VCDS triggered, it results in ASH (ash is the left over product.... think of burning a log in a camp fire... same principle)
- The above ASH will never go away, and it collects in the DPF. As you can imagine, there's a limited volume that can be stored. Once this volume is maxxed out, you need to replace the DPF as it is clogged (read FULL).

This is the reason why not every vehicle needs a replacement after the same amount of milage or use.
 

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Discussion Starter #37
I believe some of you are somewhat miss-understanding things a little.
Jumping to that conclusion, I will now attempt to give you the Cole's Notes

- Soot is what is generated by the engine, and this amount will vary based on operating conditions. Not all users will generate the same amounts based on their specific conditions, use, operating parameters, system health, driving habits, etc.
- Once a certain level of the above soot accumulated in the DPF, the system recognizes that it needs a regeneration to "clean the DPF".
- When any regen occurs, weather it is passive, active, ECU or VCDS triggered, it results in ASH (ash is the left over product.... think of burning a log in a camp fire... same principle)
- The above ASH will never go away, and it collects in the DPF. As you can imagine, there's a limited volume that can be stored. Once this volume is maxxed out, you need to replace the DPF as it is clogged (read FULL).

This is the reason why not every vehicle needs a replacement after the same amount of milage or use.
Thanks, that’s exactly my understanding.

So theoretically Touaregs that are primarily being driven on long runs vs mostly city should have less ash over lets say 100,000 or 200,000 kms.
Would be good to compare the ash loads between the two.
 

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Would be good to compare the ash loads between the two.
There are all sorts of such posts on various other TDI forums, especially 2L ones that are much more common .... There really is no point to it..... Each one of us uses our vehicles in a specific way and conditions. If my commute to work is 50mi each way, all freeway, and yours is 5mi each way through town, I very much doubt that you will get a job in another city just to reduce your ASH / mile ratio......

But I could be wrong
 

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Discussion Starter #39
Would be good to compare the ash loads between the two.
There are all sorts of such posts on various other TDI forums, especially 2L ones that are much more common .... There really is no point to it..... Each one of us uses our vehicles in a specific way and conditions. If my commute to work is 50mi each way, all freeway, and yours is 5mi each way through town, I very much doubt that you will get a job in another city just to reduce your ASH / mile ratio......

But I could be wrong
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.
 

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So theoretically Touaregs that are primarily being driven on long runs vs mostly city should have less ash over lets say 100,000 or 200,000 kms.
With everything else being the same, yes. But fuel quality, oil levels/quality, general state of the engine components and driving habits (like how much you like to floor the pedal) also have an influence on how much soot is generated, or how effective regeneration can be. Possibly even more so than whether you're driving your car mostly in city or on highways. Like a worn injector, a bad MAF, or using too much or the wrong type of oil can contribute far more to excess generation of soot - and thus also ash - than city traffic. It's just one of the negative factors, that's however not determining per se.
 
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