Is my DPF regen too often?

[toni8b]

Is there a way to check dpf levels with odbeleven?

[310golfr]

On 10/02/2017 at 12:31, Gabbo said:

 

I would say the opposite, its better that most people know nothing about the DPF or how it is working.

If I were VW I would calibrate the fan at engine stop to be half the speed (to reduce the noise so less people notice it) but run it for longer & remove the rpm increase.

 

There's too many people with a diesel worrying about the DPF for no reason, driving at 2000rpm unecessarily, leaving the engine idling until the speed goes down or driving round the neghbourhood for 20 minutes instead of getting on with more interesting things.

Unless the warning light comes on, theres nothing you need to do & for the Mk3 I don't recall anyone having problems except for higher frequency regens when doing very very short trips.

 

In my BMW, its very difficult to know if a regen is happening as the only information is the tiny StopStart off lamp (where it gives no information why).

Sometimes, less information is better.

if you know when a regen is likely to take place you can plan ahead   😎

always better not to stop a regen once it  starts,  

if you wait till the warning light comes on, you might not be in a position to keep driving.

[The1effect]

      I noticed mine is doing regeneration around 90 miles for a month now and with that a bit rough idle not much, high fuel consumption and less power. I am thinking that something like egr is clogged up or doesn't run optimally 🙄

[Ecomatt]

15 hours ago, The1effect said:

      I noticed mine is doing regeneration around 90 miles for a month now and with that a bit rough idle not much, high fuel consumption and less power. I am thinking that something like egr is clogged up or doesn't run optimally 🙄

I would use a scan tool like VCDS, OBDELEVEN to see if any fault codes are stored. It might be the DPF pressure sensor gone faulty. Either way I would not continue to drive it as you may cause further damage by doing so.

[Tivan]

Mine is doing the same, about 90miles (give or take a few) between regens since last dealer service when they did some update, last year in september. No errors ever show when scanning with OBD11, doing it regularly.

[MATT0693]

My DPF tends to be one regen per tank, on a rare occasion it will do two.

Most of my trips allow for the car to reach operating temp, so that will help reduce the frequency.

[Ecomatt]

Since changing to Millers Oil I have noticed the DPF does not fill up as quick as it did with the Quantum. My driving style is still the same so not sure why it would be any different.

[J.R.]

It would be usefull if people when posting the frequency of their DPF regens were to specify what their typical journey profile is and more importantly whether or not they have had the Dieselgate fix.

 

I cn't run a DPF app & in any case would not drive with something like that to distract me, my vehicle has had the emissions fix, before lockdown when I did as many 30 minute journeys as local short ones if not more I never heard the fans running for an interrupted regen, I did notice them when driving and would say that there would be two per pank of diesel = 600 miles, looking at VCDS I never saw more than 220kms since last regen but I never made a note of the mileages or checked more often.

 

Now with shorter journeys I frequently interrupt regens when shutting down and I reckon they are happening every 100 miles even when I have done most of that on motorways towing a very heavy and large trailer.

 

Does anyone know the soot threshold or DPF differential pressure that triggers a regen on a 2.0 TDi CR engine with emissions fix? Also the threshold to finish a regen?

[J.R.]

I have noticed that the calculated soot values are always higher than the measured ones which correspond with the differential pressure readings, does the system trigger a regen based on measured or calculated values, it seems to be the latter on my vehicle.

 

My EGR is disabled thanks to an emulator and I think that the engine now puts less soot through the DPF explaining the disparity between the measured and calculated values.

 

Another question, when the ECU says that the DPF must be replaced is it from the differential pressure sensor readings or from the estimated oil ash mass/volume?

[BogdanB]

The regen is triggered by either one of them once thet reach 24g ( I think, or something close to that ). A regen will also trigger above 80% if you are on a motorway or some high speed road. I've noticed that if I drive at a constant 100km/h for a few minutes it will start a regen even if it's not at 100% or near it.

[The1effect]

On 22/10/2021 at 09:05, Ecomatt said:

I would use a scan tool like VCDS, OBDELEVEN to see if any fault codes are stored. It might be the DPF pressure sensor gone faulty. Either way I would not continue to drive it as you may cause further damage by doing so.

I give it a hard acceleration on hill about 10 minutes and keep it at 3000 rpm and it start running smoothly on idle , also I fell it more powerful. Can't believe it, I think I've cleaned  some injectors, and this after two months of running sluggish. Hope it helps someone 

[J.R.]

I did a scan and found that it had been 180 miles since the last regen most of which was autoroute France to UK, then it was local journeys and it regenned at 240 miles which left me wondering where I had got the 90 miles from.

 

Since then I have done 700 miles of autoroutes during which time it either did passive regens or proper ones, on Saturday I interrupted a regen, I did 2 journeys later that were long and fast enough for it to complete, I did the same journeys the again the next day and was dismayed to find it regenning once again after them when only 90 miles had passed.

 

One thing that I know for sure is that the measured readings never get anywhere near the threshold and most of the regens are just wasting fuel.

 

My car has now gone over the 100K miles mark (I missed it happening ) and would really like to know how the 0.1l oil ash volume it believes it has corresponds to the threshold where it must be replaced or perhaps cleaned, the only figures I have seen quoted are in grammes, does anybody know?

 

[BogdanB]

The ash is an estimate. You will know it has to be *cleaned* (wouldn't advise totally replacing if cleaning is a cheap option where you live) when you can't drive 5km without triggering a regen.   

Also, I wouldn't look at distance between regens, but TIME between regens. I can get 400km or 100km between regens, depending on city/highway driving.  But the time is almost the same every time. On the highway I might get passive regens which help a bit with the interval. 

As long as you don't hear your fans running every time you stop the car, I wouldn't bother. ( Had this happening to me, never being able to complete a regen and fans always running ).

[The1effect]

What about oil mass? Is there any method of cleaning it or the dpf has to be changed?

[BogdanB]

That's the thing that gets cleaned actually. When 'washing' the dpf.

[J.R.]

Very pragmatic advice BogdanB.

 

It probably is simply driving time generated and all the numbers being a red herring unless one goes beyond the threshold.

 

When the stars are aligned I will have a rollback done of the emissions fix which should reduce the frequency massively.

[gm73]

On 09/02/2017 at 15:41, donny1972 said:

Afternoon folks, I have had my 63 plate octavia vrs diesel for almost 2 weeks now and so far very impressed with it. I have covered about 360 miles so far and the car has done a regen at least 3 times  going by the 1k revs tickover.  My problem is that today it started doing another regen prob about 90 miles from the last one. Is this normal or is my DPF doing too many regens? 

 

 

I sold my 15 plate 1.6 TDi CR with 200k miles

on it and it it constantly regenerated so I wouldn’t worry about it. The new owner has covered another 10k and it’s still going strong with no DPF issues. 

[BogdanB]

1 hour ago, J.R. said:

Very pragmatic advice BogdanB.

 

It probably is simply driving time generated and all the numbers being a red herring unless one goes beyond the threshold.

 

When the stars are aligned I will have a rollback done of the emissions fix which should reduce the frequency massively.

In theory this is how the load models are calculated.

 

 

The first model seems to be 'soot mass calculated' which rises steadily ( thus determining almost the same driving time between regens ), and the second one, 'soot mass measured' .

So, even if your DPF is full, the soot mass calculated would show a lesser value, depending on 'time running'.  

 

When my DPF was clogged this is what would happen: 

1) Regen running, only completing on idle. 

2) Soot mass calculated steadily going up 

3) Soot mass measured spiking to almost 100% ( 24g) when starting to drive away 

4) Few seconds into driving, a new regen starting, triggered by soot mass measured, even if soot mass calculated was at around ~5g

Edited 2 November, 2021 by BogdanB

[The1effect]

   I just noticed the dpf regeneration started when engine was almost cold , or in 5 min after starting it, 10 degrees C outside. This is contrary of what I knew. The coolant needle was a bit over 50 C and the engine warm up faster than normal. I was expecting to regenerate as it does after 120 mile( city driving all times) but never with engine cold. Another thing I noticed, it doesn't matter if you push it hard when regeneration it taking place, it will take same time or even longer than just idling in car park and waiting to finish ( usually 10 min) . For the ones that don't know , if engine is hot (90 C) and rpm is at 1000 then don't turn off, leave it until is finished and start dropping, it doesn't take much time. You can go around the car and feel the burnt rubber smell just to be sure, it will save you from dpf trouble in the future

[J.R.]

Are you sure that under the conditions you describe the regen is actually continuing and finishing or simply the fans running because the DPF is critically hot from the interrupted regen when you were driving?

 

I would love to believe that you are right but when I was rebuilding my Yeti it got moved from place to place in my parking area, in and out of the garage etc over a few weeks, never driven on the road, eventually I heard the fans running on switch off so I knew it had tried to regen, I left it ticking over for a long time until the fans stopped thinking like you that I had allowed it to regen, but once warmed up it would try again, fans running when I switched off.

 

I repeated the idling regen several times once for nearly an hour, very soon after that and with zero miles driven the DPF warning light came on telling me I had to take it for a spirited drive. Luckily I had finished the repairs by then so after getting the engine warm I drove between junctions on the A23 and the light went out within around 5 miles.

 

My car regenning every 90 miles like at present I believe is in fact several attempts to do the same regen, I found in VCDS that 240 kms had elapsed since the last regen and then drove another 40kms before it regenned, then I did 190 autoroute miles to Picardie followed by 550 miles the next day to Nouvelle Aquitaine. I was dismayed to hear it regen the very next day and do the same 3 days on the trot even though I had driven 100 miles on each day, but they were slow rural trips househunting with many stops, I am convinced that it was the same regen never having the right conditions to complete.

 

 

Edited 7 November, 2021 by J.R.

[BogdanB]

A regen can indeed complete at idle. But not in 10 min. It usually takes around half an hour. 

I have watched a lot of regents using vag DPF / vcds. 

At idle, it struggles to keep the temperature up and it uses way more fuel for the post injection. 

While doing it on the highway, it does minimal post injection and it finishes in around 10 to 15 min. 

[The1effect]

    Let me explain more in details my driving conditions, when the regeneration is happening and why I believe is that so.

   I bought this car with high mileage and I am looking at everything to make sure is working properly.  When the dpf measured or calculated values are around 22g I expect it to happen soon, I am turning radio volume low/off, so I can hear the engine noise change when is active while idling,  use vehicle data- instant fuel consumption on dashboard screen to see the actual values ( use l/km units as mpg doesn't show anything on idle) this is usually around 0.5 or 0.6 l/km ( no ac, headlights or heated mirrors in use) with the engine warm and 1.0 l/km or more when regeneration is active.  Rmp is at 760 ( same, warm engine, no accessories on) and around 1k when regenerating. If I am already at destination I'll wait around 10 to 15 minutes until it finishes. If it takes more I'll raised the rpm  a bit to see if it drops back to 760 if not then is still regenerating. And walk around the car to feel the burnt rubber smell as another confirmation, don't put you hand close to exhaust as the fumes burns like hell. 
  After everything returns to normal I'll wait 2 minutes to let the system cool off and then turn off the engine, never heard the fans working afterwards. Checking the soot level it shows values between -5 and 5 grams on both measured and calculated and I tried many times concluding that is how regenerating is taking place.
     I drive around 10 miles in 20 minutes in the morning and same distance and 50 minutes in the evening, in weekends is slightly different but not much, I refuel only from Shell and Esso (UK), the test was made in September-October and I believe in summer time it will take less time, I rarely use start stop, it won't work anyway when regenerates.
     This is my experience with my car, to note not every car is the same and the  conditions might be different.

 

[BogdanB]

45 minutes ago, The1effect said:

    Let me explain more in details my driving conditions, when the regeneration is happening and why I believe is that so.

   I bought this car with high mileage and I am looking at everything to make sure is working properly.  When the dpf measured or calculated values are around 22g I expect it to happen soon, I am turning radio volume low/off, so I can hear the engine noise change when is active while idling,  use vehicle data- instant fuel consumption on dashboard screen to see the actual values ( use l/km units as mpg doesn't show anything on idle) this is usually around 0.5 or 0.6 l/km ( no ac, headlights or heated mirrors in use) with the engine warm and 1.0 l/km or more when regeneration is active.  Rmp is at 760 ( same, warm engine, no accessories on) and around 1k when regenerating. If I am already at destination I'll wait around 10 to 15 minutes until it finishes. If it takes more I'll raised the rpm  a bit to see if it drops back to 760 if not then is still regenerating. And walk around the car to feel the burnt rubber smell as another confirmation, don't put you hand close to exhaust as the fumes burns like hell. 
  After everything returns to normal I'll wait 2 minutes to let the system cool off and then turn off the engine, never heard the fans working afterwards. Checking the soot level it shows values between -5 and 5 grams on both measured and calculated and I tried many times concluding that is how regenerating is taking place.
     I drive around 10 miles in 20 minutes in the morning and same distance and 50 minutes in the evening, in weekends is slightly different but not much, I refuel only from Shell and Esso (UK), the test was made in September-October and I believe in summer time it will take less time, I rarely use start stop, it won't work anyway when regenerates.
     This is my experience with my car, to note not every car is the same and the  conditions might be different.

 

That sounds as normal behavior. I would only add to it that the idle can go to 1k and 1.0l consumption for other reasons too. 

The besy way to tell if you are in an active regen ( if you dont own VCDS, VAG DPF or any other related software) , you can check the START/STOP screen in the infotainment system, and it shows that it's disabled due to "ENGINE MUST BE RUNNING".

[The1effect]

   I specified that engine needs to be warm or optimal temperature and the all accessories off  ( like ac, headlights , heated seats or mirrors etc.), start stop won't work and outside temperature matching September-October .  What are the other reasons that I didn't mention ? 🤔

 

[BogdanB]

Yeah, I forgot about saying that engine is up to temperature. Then, indeed, only the regen will bump up the revs.