11 minutes ago, OldBoyScout said:

u missed out the scenario where the DPF light comes on and the driver doesn't ignore it, but drives according to the instructions in the manual. I would say that was the Forced Regeneration, 

 

 

If we are going to be pedantic here, a forced regen is when you actively tell the car to regenerate with diagnostics, if the car is wanting to a do a regen of its own accord you are not 'forcing anything'. So in my eyes you are just letting it carry out its active regen.

 

 

 

Geewiz gents are we not splitting hairs over terminology here? Shall we not just conclude that there were many dpf issues on the older variants and much less so on the latest models but still the occasional issue cropping up and that there are several kinds of regen' under one name or another. 

Edited 22 September, 20196 yr by Gmac983

37 minutes ago, SuperbTWM said:

If we are going to be pedantic here, a forced regen is when you actively tell the car to regenerate with diagnostics, if the car is wanting to a do a regen of its own accord you are not 'forcing anything'. So in my eyes you are just letting it carry out its active regen

OK I think I get that now.  When you actively tell the car to regenerate with diagnostics it is not an active regen but a forced regen, and when the car is unable to do the regen of its own accord and you have to force the issue by driving in the prescribed manner it is not a forced regen but an active regen.  😉

 

32 minutes ago, OldBoyScout said:

and when the car is unable to do the regen of its own accord and you have to force the issue by driving in the prescribed manner it is not a forced regen but an active regen.  😉

 

 

Yes, but an active regen is not exclusively for when the DPF light comes on.

 

'Active' just means that the ECU has picked up that the diff pressure across the DPF is too high and needs to regenerate and is adjusting injector timing to enable the DPF to get stinking hot. It does this without you knowing (although obviously if you stop you will notice the increased idle, hear the engine fan and possibly smell burning)

 

1 hour ago, Gmac983 said:

Geewiz gents are we not splitting hairs over terminology here? Shall we not just conclude that there were many dpf issues on the older variants and much less so on the latest models but still the occasional issue cropping up and that there are several kinds of regen' under one name or another. 

 

Where's the fun in that 

1 hour ago, SuperbTWM said:

Yes, but an active regen is not exclusively for when the DPF light comes on.

I knew that, I was just attempting a bit of humour, hence the emoji. It was I who pointed out in the first place that the members who used the term passive were describing an active regen. (or at least two of us posted that simultaneously).

It was also my oblique way of acknowledging that I had used the term forced incorrectly and had been corrected.

Edited 22 September, 20196 yr by OldBoyScout
Added a bit.

Sorry @OldBoyScout went straight over my head 

 

 

Edited 24 September, 20196 yr by SuperbTWM

For interest, I drove to work on Friday. Just over an hour’s drive with the first 40 minutes on A roads, 20 minutes on dual carriageway, and the final 5 minutes at town speeds. Just after I’d started the “town” section of the journey, the car decided it needed to do an active regeneration. 
 

My point being that I’ve found that to be reasonably typical behaviour - you can do all the long fast journeys you like, but the car will decide when it needs to regenerate the DPF, and it just gets on with it. Unless the warning light comes on, you just need to drive it as normal and it sorts itself out. 

On 28/09/2019 at 16:27, MrTrilby said:

My point being that I’ve found that to be reasonably typical behaviour - you can do all the long fast journeys you like, but the car will decide when it needs to regenerate the DPF, and it just gets on with it. Unless the warning light comes on, you just need to drive it as normal and it sorts itself out. 

 

In addition I just wanted to add my two penneth about passive regeneration.

 

 last Monday on my way home from work I pulled on the drive and interrupted the regen it was doing. This was after 40 miles of 70mph cruising so this basically proves that at cruising speeds there is no passive regeneration at all, at least on my car/engine combination.

 

After driving to work all week the car then decides to do another regen yesterday, again, if we were getting any sort of passive regeneration going on, it wouldn't of needed to do and 'active' one after 400 miles.

5 hours ago, SuperbTWM said:

After driving to work all week the car then decides to do another regen yesterday, again, if we were getting any sort of passive regeneration going on, it wouldn't of needed to do and 'active' one after 400 miles.

Was there any active regen between the interrupted one last Monday and the one on Saturday?  As the Monday regen was interrupted, can you be confident about drawing any conclusions from the fact that another regen was initiated 400 miles later?  If I understand it correctly, it is quite normal for another attempt at active regen to follow one that has been interrupted.

 

 

10 hours ago, SuperbTWM said:

last Monday on my way home from work I pulled on the drive and interrupted the regen it was doing. This was after 40 miles of 70mph cruising so this basically proves that at cruising speeds there is no passive regeneration at all, at least on my car/engine combination.

 

There is passive regen going on all the time. But you wouldn`t notice ie without equipment, VAG DPF for example.

 

The car starts active regen latest after every 650 - 660 km, even if DPF is only partly filled. 

1 hour ago, linni said:

There is passive regen going on all the time. But you wouldn`t notice ie without equipment, VAG DPF for example.

Quote from VW Technical Support:

"During long motorway journeys, passive regeneration will occur. This needs no intervention from the engine control unit. Due to the raised exhaust temperatures on a long journey (temperatures between 350 and 500°C), the procedure occurs slowly and continuously across the catalytic-coated (with platinum) DPF. The catalytic-coated DPF is situated close to the Engine, therefore the exhaust gas temperature is high enough (500°C) to ignite the soot particles. Due to this soot is burned-off and is converted into a smaller amount of ash"

 

So it is not actually going on all the time, but will be going on if the exhaust gas temperature is high enough.

 

2 hours ago, linni said:

The car starts active regen latest after every 650 - 660 km, even if DPF is only partly filled. 

Further quote from VW Technical Support:

"Active ‘regeneration’ is when the ECU intervenes when the soot loading in the DPF is calculated to be 45%."

 

So it depends on calculated soot loading (45%) rather than distance covered.

 

You can find the full article here: https://www.briskoda.net/forums/topic/301020-my-new-diesel-smells-like-burning-rubber-andor-the-fan-stays-on-after-engine-is-turned-off/page/4/

 

 

3 hours ago, linni said:

 

There is passive regen going on all the time. But you wouldn`t notice ie without equipment, VAG DPF for example.

 

The car starts active regen latest after every 650 - 660 km, even if DPF is only partly filled. 

 

I think I’m going to have to do some logging and settle it once and for all because i’m not convinced at all. 

 

 

42 minutes ago, OldBoyScout said:

so it depends on calculated soot loading (45%) rather than distance covered.

 

No, it doesn`t. VW Technical support can write whatever they like, but my remarks are based on actual and personal experience since Superb II dieselgate.

Whatever the soot load is, in every 660 kilometers active regen is performed. Lowest soot load I can remember was something 30 + percent.

Have been driving with VAG DPF on phone screen couple of hundred thousand kilometers.

 

48 minutes ago, OldBoyScout said:

During long motorway journeys, passive regeneration will occur

 

Of course the passive regen will not be on literally all the time . But quite constantly.

29 minutes ago, linni said:

Whatever the soot load is, in every 660 kilometers active regen is performed.

Yes, that would equate to 412.5 miles which is pretty close to the 400 stated by SuperbTWM.