Hi , hope someone can shed some light on a this . On an 2021 Octavia fault says. The regeneration frequency of Diesel Particulate Filter is not ok , says the fault is permanent . Car is due to go for software update , would this have something to do with it. Thanks

That means the dpf isn’t getting to regen frequently enough. What kind of driving does the car do?

I drive 30 miles a day on rural roads at 60 mph and a few long drives at the weekend.

Okay, should be long enough, but the rpm may be too low. the DPF system needs a sustained run over 40mph and rpm between 2000 - 2500rpm.

In my mk2 that means sitting about 55-60mph in 4th gear (5speed manual, your gearing may vary), and for about 15-20mins to complete the regen process

I’m having a problem understanding this. Recently (Jan) bought my 4th Octavia 2.0L diesel (2022) and never had a problem with the previous 3 (but coincidentally I am now doing fewer miles). It was 75k miles as it was a rep’s car. Had done about 5k when I got the “reduce oil” message and the garage siphoned some off. I bought the VAG DPF app and it tells me it did a regen last week as I did a return journey of about 140 miles on motorways.

Today I did a brisk return journey of about 50 miles and monitored it on the app.

So it’s now 133 miles since the last regen and the soot is now at 78%.

What I’m struggling with-

1) At 70mph my revs are only about 1700 in 6th, but it must have done a regen during that 140 miles (not driving it hard in low gear as has been quoted).

2) Will it regen as the soot approaches 100% or after a certain mileage- it’s a pity there couldn’t be a display on the dash to signal this.

3) Failed regens- is this because you stop the engine mid-regen or just slow down, or do they just fail sometimes?

I watched a YouTube where they monitored a Yeti and it showed the exhaust output reaching well over 300 degrees c after maybe 10 miles, driven sensibly, and the graphic on the app turned pink. However on my trip today I struggled to get it much over about 280c.

It's practically a certainty that your current reduced mileage and DPF issues are not a coincidence.

The excess oil will have been diesel fuel from failed regens.

Edited Saturday at 21:183 days by Warrior193
typo

My personal experience with my mk3 diesel that all of this running at a certain speed, certain revs etc is not nessasary. Yes, it would take longer but would just raise the idle speed a bit and would do it sitting on the driveway happily.

1 hour ago, MeteorOcty said:

My personal experience with my mk3 diesel that all of this running at a certain speed, certain revs etc is not nessasary. Yes, it would take longer but would just raise the idle speed a bit and would do it sitting on the driveway happily.

I would have to agree with this, as my one experience of using the app this week seems to back it up. I need to monitor this over the next months as I may have to change to petrol after 35 years 😜

As warrior pointed out the excess oil will have been diluted by diesel. I personally would be inclined to get an oil change done as you don't know how much diesel was in oil or how much oil was removed. Surprised the garage didn't say something unless it was a small amount as I cars use oil not create it. Too much diesel can eventually lead to problems and worse case scenario it gets past the turbo seals and causes run on. Having the same problem with my mk2 1.6tdi. Used to do decent mileage but not any more. On mine it makes a slight noise during regen and revs at idle are around 1200. When it happens if I can I continue driving and take it for a decent blast in 3rd/4th to keep revs up until idle becomes normal (about 20mins). On mine a failed regen puts fans on when I turn of engine.

Alasdair

1 hour ago, Alasdair1 said:

As warrior pointed out the excess oil will have been diluted by diesel. I personally would be inclined to get an oil change done as you don't know how much diesel was in oil or how much oil was removed. Surprised the garage didn't say something unless it was a small amount as I cars use oil not create it. Too much diesel can eventually lead to problems and worse case scenario it gets past the turbo seals and causes run on. Having the same problem with my mk2 1.6tdi. Used to do decent mileage but not any more. On mine it makes a slight noise during regen and revs at idle are around 1200. When it happens if I can I continue driving and take it for a decent blast in 3rd/4th to keep revs up until idle becomes normal (about 20mins). On mine a failed regen puts fans on when I turn of engine.

Alasdair

Thanks Alasdair. Yes I’m getting an oil change next week. I’ve been reading up on all this for a couple of weeks now and it was scaring the **** out of me although the garage didn’t seem to share my sense of urgency. Tbf they’re usually brilliant and I’ve been going there for over 30 years. Anyway I got the app the other day and I’m a bit more clued up after using it, and I can try and predict when a regen is due.

I only got the car in January and my previous one was a 2014 so was Euro 5, less complicated but couldn’t go near the LEZ in town.

Glad your getting an oil change. One bonus is that you will have a very clean engine

Same here re LEZ pain in the a**e but cant do anything about it. Lucky Inverness hasn't got one. Found on mine if your fans come on after engine switch off its a failed dpf regen so needs a good run down a dual carriage next time which wont do a diesel engine any harm.

Alasdair

2 minutes ago, Alasdair1 said:

Glad your getting an oil change. One bonus is that you will have a very clean engine

Same here re LEZ pain in the a**e but cant do anything about it. Lucky Inverness hasn't got one. Found on mine if your fans come on after engine switch off its a failed dpf regen so needs a good run down a dual carriage next time which wont do a diesel engine any harm.

Alasdair

I'm near Edinburgh so usually get the bus in. Got loads of mates in Sneck, I've got a season ticket at ICT but don't go up much these days.