Deadwood

And to follow up, quickly, what can you do to minimise the effects of this "feature"? The two big things seem to be: 1) Recognise that a big diesel isn't designed for short, slow runs. It needs to stretch its legs. Give it a run occasionally, especially in winter when 2 minutes to the shop are all it usually does. Apparently you need to find a road where you can keep speed up to about 50+mph and revs over 2,000 for half an hour so so to allow a regen to work. In the UK this means a motorway run. 🙄 Esp with DSG. 2) Recognise when it is in regen. Apparently signs are tick over about 1,000rpm rather than 800, slightly rough running and Auto Stop/Start unavailable. Watch for these before you switch off at the end of a run. There is a school of thought that says if you get home and these factors apply, go for a brisk whizz round the block until tickover's back down to 800. Sounds like a faff to me.

🤣Yes, well, back to the case in hand! So, after a bit of reading, it looks as if the situation is a bit like this: Basically, fuel in the oil is an inevitable fact of life for anyone driving a car with a diesel engine, a DPF and a "post-injection" system for regenerating the DPF. The "post-injection" bit basically means pumping fuel into the cyclinder during late-phase power or exhaust strokes to pump it down the exhaust to the DPF where it bursts into flames and cleans 'said DPF. Inevitably some of that fuel washes down the cylinder wall, past the piston rings and into the sump. Failed regens lose no more fuel than successful ones, by the look of it, but it's the re-tries that kill you - simply the number of re-tries. So, yes, the level in the sump will go up after every regen and much more obviously so after 10 or so failed regens in rapid succession! So, does it get burnt off? Well I think we all know the answer to that; there is no active method of recovering the fuel and "burning it off". However, there is some support for the theory that if the oil/fuel mix gets hot enough (100°C or so) for long enough (guessing hours rather than minutes) on a long run, then the diesel being lighter than the lub oil will evaporate first, and the vapour will be syphoned off by crankcase breather/ recycler scavenger systems that might be fitted. What proportion of the fuel is removed via this process is open to debate. Does it impair the oil? On a binary scale, certainly. On a more graduated scale, the quality of lub oil degrades with usage, so there must be some degree of degradation that can be tolerated without unduly damaging the engine. One would think. Particularly if allowing fuel to leak into it is a "design feature". So, yes it still impairs the oil, but hopefully within acceptable/ tolerable limits. So what do we think happened to my car? Well, it was due an oil change, so was probably carrying a fair load of fuel in oil, which triggered the overfill warning just before the oil change. The oil was changed and topped up to the full mark. It being the depths of winter, short days, short, slow journeys, etc., a regen or two later, a finnicky sensor kicks off. There are no fault codes that would suggest a failed regen, and the amount of "overfill" visible on the dipstick is, well, invisible! Armed with that background, absence of fault codes and the knowledge that the dealership I spoke to acknowledge the situation by filling to slightly shy of full, we've dropped 300ml of oil, and will keep a close eye on it. If the same warning comes back in short order, oil and filter change again (groan) and then we've got some more serious diagnostics to do. Thanks to everyone for their thoughts and advice.

Midgets were always too tight for me! But yeah, the rest can fit in a B. She's tight as a drum. The Bounty had seen better years, stopped there about three years ago round Christmas as we couldn't get in at Whitewell. Great breakfast! No longer open. Great shame, it was a great place in the day. Decent food and decent beer.

🤣 Would love Tartan or Damask chrome, but I am beholden to a slightly scruffy, but mechanically good '78 GT. She did Toulouse in '24, broke my hip last year, so need to start warming her up again! So 8/10 for Sherlock Skills! I think she might have instilled the idea you might need to persist beyond a warning light... Whether that's a good position to take in this day and age is debatable! 🤣

All at normal ops or within a few moments of stopping. Flat ground. Not done cold comps.

Good points, all of them. I have been a high mileage motorway driver for years and wanted to stick with 2.0l diesel simply from comfort zone. The wife's 1400 Fiesta terrifies me! Anyway, I found out many things this afternoon, I'll post a summary in case it helps anyone else. The dipstick was at max - not over. So we've dropped about 300-400ml (it's a litre from max to min) and we'll see how we go. I take your point about just getting shut, but we'll see. My other car is an MG 🤣

This appears to be key. The contamination is unavoidable, and appears to be deemed "within tolerances" for successful regens. Repeated failed regens cause the problem. Having done >300km in a Pug which used the same regen system, I'm more relaxed. Now, the manual Pug encouraged shall we say, "spirited" driving. The Octa with DSG, winter, short trips doesn't, really. Still very quick off the mark, but still less , well, spirited. Anyway, I'll post a more logical summary if my research shortly! Thanks to everyone for their input.

Thanks, all. Spoke with dealer service dept, and I'm not sure whether the mystery is solved but this is what they said... Yes, a failed regen will dump fuel (about 200ml by inference) into the oil, but this doesn't matter as it gets burned off later. (Not too convinced about that, unless it's something like the oil/fuel gets hot, fuel evaporates first and fumes are scavenged for reuse. 🤷) Also the oil level rises after a successful regen as well! (Not sure why, though. What's entering the system? Can't be burned fuel... ) Anyway, the dealer workaround, they say, is to fill the oil 200-250ml shy of the full mark to allow for the regen process without triggering the overfill warning. 🫣 The other question is if the oil level rises after a successful regen, why isn't oil spraying out of the filler like a fountain? 🤔

Good, if unpleasant thought. 3yo/ 75k, so on the lower end of my list of possibilities, but deffo worth considering.

I wonder if I could draw upon the group's collective wisdom on this one? Last week I got the "bing" of death and a message about removing some oil popped up along with a yellow oil can and exclamation mark. As an oil change was scheduled for the day after, I didn't really worry about it other than to do a quick Google which suggested that the cause was a failed DPF regen dumping about 200ml of diesel into the oil. 😳 Sure enough, oil and filter change fixed the issue. Or so it seemed. Three days later, pottering up motorway, put foot down, bing of death and associated illuminations. So, further research reveals that the internet is roughly evenly split amongst four solutions: A - Do nothing and ignore it. B - Drain/ Syphon 200ml or so of oil / diesel off. C - Go for a half hour low gear, high revs thrash (easier said than done with a DSG) D - Proceed straight to workshop for oil and filter change. Do not pass Go, do not collect £200. Obviously only the last option addresses the level and contamination issues, but an oil change every week is going to work out expensive. So, what is the collective wisdom? Is 200ml of diesel in, what, 5 litres(?) of oil a big issue? Does the system recognise the failure and stop retrying or will it just keep dumping fuel into the sump? Have I just been unlucky or do I need to start investigating the reasons why DPF regen is failing? Has anyone else been this way before and how did they solve it? Any advice / experience gratefully received.

Complete Skoda newbie here. Mk IV Octavia with Bolero or Columbus infotainment. Still haven't worked that one out. Anyway. I connected my Pixel 8 via Bluetooth. That kinda worked, I could use it as a media source, and I could initiate playing music from the phone. OK, but a bit clunky. Then I was prompted to use Android Auto. This, in retrospect, looks like a mistake. Admittedly, it meant I could play music on my phone by tapping the infot screen, and lots of other things I'd never really want to do while driving. So, I put an album on. Then I decided I wanted to listen to the radio. However. Each time I get back in the car, the radio cranks up and then Android Auto takes over, and Walk like an Egyptian starts. Now don't get me wrong, I'm as big a fan of Susannah Hoffs as the next man, maybe more, but I wouldn't mind the option of not having her play WLAE every time I get in the car. I've tried going into AA on the infot panel and "forgetting" the device, but every time I re-pair Bluetooth, AA takes over and WLAE takes over. Any ideas gratefully received!

Skoda newbie, Mk IV Octavia SE Tech. Baffled!