cybernck

Great, thanks for the very valuable input @BogdanB and @varooom Additionally, I've just stumbled upon an article (about diesel trucks though) that states that 90% of ash in the DPF is formed by way of combusting engine oil. Therefore, for anyone reading this in the future - we now have a definite conclusion in terms of cleaning the DPF along with the engine using excessive amounts of oil - no point in doing it.

Your postulate is wrong here as in this case water should also contain some arsenic to begin with for the logic to be correct. To my understanding - combusted diesel will release soot particles that DPF will catch and later burn, which in turn will leave ash residue in the DPF. Combusting (excessive amounts of) engine oil is bad will eventually create ash and/or other forms of deposits in the DPF as well - there's no question about it. So, it all just comes down to the designed/expected ratio of diesel to oil during the course of life of a DPF filter. If 1 liter of combusted engine oil will produce as much ash as the quantity of diesel required for 200.000 km of driving - then of course it's all but negligible and a car with very high oil consumption will still do very frequent DPF regens and the filter will get clogged up very quickly. Rather than theoreticising about it, it can be calculated based on scientific data OR - more importantly - if someone was in the same shoes as me and can tell us their findings based on getting the DPF cleaned but still sticking with worn piston rings (or whatever) - that should provide us with a pretty good answer. So, until someone shares their PRACTICAL experience or I do it myself to find out - I guess we won't have a definitive answer to it and we're just wasting time discussing it and doing the guesswork. Cheers,

Yes, that's my understanding as well, considering I estimate it at about 0.005 liters of oil per 1 liter of diesel. Will be a touch more oil per liter of diesel once the constant regenerations stop and the car starts using less fuel.

@roottootYes, by big service I meant cambelt, waterpump etc at 210k km (as compared to the small service which is just oil and filters). Just a terminology we use here. It's a general consensus here on the forum that it's the 30k km service interval that kills these engines. @EcomattSure, it will eventually clog up again, be it in 1k, 10k or 100k kilometers. But my question is if it will operate fine until it gets clogged up again or will the temporary soot levels still be high and trigger frequent regenerations just due to the excessive engine oil consumption.

@BogdanB- Hi, it looks like I'm experiencing exactly the same symptoms and somewhere else I read that you scheduled the engine rebuild soon, due to high oil consumption - so it's exactly the same case as well. I'm just wondering if you did get your DPF cleaned last year and - if so - what's has it been like with DPF regens since then? Thanks.

@dowding- Hi, what have you ended up doing with the DPF (or the car altogether)? I'm wondering, as I happen to be in your shoes right now 😞. You can PM me if you wish. Thanks.

You're telling me what I already know fully well. But opening the engine is not an option, so I'm trying to establish if it's worth doing *anything* to the car, considering there's a big service coming up very shortly as well. It must have been buring oil already long before I got it anyway. The car was on Skoda's dreaded 30k km "flexible servicing interval", which is known to kill the badly designed oil piston rings.

Yes, I agree with that. But the point is that the ash residue has developed over the course of 200k km (or probably less, as it had already been like it when I got it back at 187k). So, the question is - if I get the DPF cleaned, will it be fine for the next 50k or so? Or will engine oil trigger the regenerations straight away anyway?

Hi, thanks for the reply. Did you mean that the oil consumption is the culprit directly or by way of getting the DPF clogged up? Or in other words, do you think constant regenerations would still happen even with a fresh clean DPF? I don't find it logical that 0.005 liters of oil per 1 liter of diesel can create such a havoc really 😃 As far as I know, the diagnostics don't bring up any issues with DPF related sensors.

Hello, long time forum lurker and a 2015 Skoda Octavia Mk3 vRS Diesel owner for a year now. It's been my dream daily car since its debut but unfortunately I've been burdened by both high fuel and high oil consumption since the first day of my ownership. I've done a lot of research and it looks like not much can be done about the oil consumption (6 liters on 15,000 km - if I've kept track correctly) without an engine rebuild. On the other hand, I've traced the high fuel consumption (between 1 and 3 liters over what board computer states and what I would expect) to DPF regenerations happening far too often. I've recently equipped myself with Vgate Pro and VAG DPF app, so I've been able to confirm that the regeneration is taking place almost non-stop. Oil ash residue is a bit high for the mileage (204,000 kilometers) at 62g or 77% but other VAG engines seem to function normally with that sort of oil ash residue. However, what confuses me is the soot residue gets a sudden spike from 8g to 23g and starts the lengthy regeneration process. Sometimes it drops down suddenly as well. I'm failing to understand if the DPF filter is actually clogged OR if it's the engine oil burning causing it OR if there's a problem with some DPF sensor. The last thing I want is to clean the DPF filter or even do an engine rebuild and have the same issues coming up! Thanks.