Pjn90

Whilst i was trying to solve this issue someone once said that when the car is doing a regen it gets that hot the oil would thin that much it would seep past the rings and burn. My theory is that when the car was new and it would only regen every 300-400 miles oil consumption wouldn’t be as bad. But as these engine have fairly loose rings to help with economy and performance they naturally burn oil anyway. The ash from the oil that can’t be burnt off through a regen will gradually block the dpf which would cause the regen to happen sooner which means more oil would burn meaning more ash being stored in the dpf to the point where it would regen every 10 miles because the ash in the dpf is triggering a regen because of the differential pressure reading already being high from the ash so a small bit of soot will trigger a regen. if anyone here is mechanically minded I would suggest removing dpf and getting it properly cleaned removing the ash so its as near new condition and then see how this effects the oil consumption and regens. Unfortunately removing the dpf isnt a straight forward task on these engines and i was quoted £1300 for removal, cleaning and refitting. But if you can do the removal and refit yourself the cleaning cost is only around £100-200. Obviously £1300 is alot of money to spend on a car that could potentially need an engine rebuild or replacement but fingers crossed the piston ring failure in this post was a freak one off. when i got rid of my car i had just had a new born baby, not getting any sleep and at the time couldn’t be doing with the stress of potentially a knackered engine. But now things at home have settled and my head is in the right place again i truely regret selling my octy. I wish now i would of taken dpf off and had it cleaned as im fairly certain the engine in my car was absolutely fine and it was just the stupid!! Dpf! Yet again causing more problems. im seeing this issue popping up more and more. Hopefully a solution will be found soon.

Hiya i ended up selling the car but the only thing i could assume it must of been is the dpf is full of ash which cant be burnt off through a dpf regen. The car has always burnt oil through its life and gradually got worse to the point it was burning around 500ml every 1000 miles. Which i am assuming has caused the dpf to clog prematurely because I think 80% of the ash accumulation in the dpf is from oil. only thing that i can think of that caused the excessive oil consumption is from the engine getting really hot due to the constant heat from the regens and then obviously that would cause more ash in dpf and then it would snow ball effect into the problem we are now experiencing. If you are mechanically minded I would suggest removing dpf and then getting it properly cleaned back to near new. The cleaning process is only around £200 but the removal and installation isnt so straight forward. I think it involves dropping sub frame, removing drive shaft and then you can remove it. But during installation you have to tighten the bolts holding the dpf in place to a very strict procedure so that it doesn’t work loose from the extreme temperatures. I got quoted £1300 for removal, clean and installation which i accepted! But then the company wouldn’t reply to emails or answer phone so i am guessing they didn’t want the job and was hoping i didn’t accept that quote. I tried 3 places to diagnose problem and all 3 couldn’t see anything that could be causing it other than a clogged dpf. I was recommended to a diesel specialist in Loughborough that apparantly are really good at solving these types of issues but i got rid of car before trying them. I think they are called tt automotive or something that starts with tt

I no longer have my mk3 octy as I regrettably sold it due to the reason i had a mk2 octy vrs which had the same oil consumption as my recent mk3 and 12 months into ownership or 100k miles piston rings went on cylinder 4 even though the car ran spot on up until that dreaded day. As my mk3 octy just coming up 100k miles and with identical oil consumption i just didn’t want to take the risk. But after i sold the car i suddenly thought would a simple engine flush resolve the issue and prevent potential piston failure as it could just may be that carbon and sludge build up is causing the rings to stick. Just curious to see if any of you have done an engine flush? As i wish now i would of done that before getting rid of the car as i truly miss driving it and regret selling it every day as it could of unknowingly done another 100k miles.

I do an oil change every 6-12 months and its always the same. I think the best thing is just to trade it in. I had a mk2 octy vrs and piston rings went on that at 100k miles and the oil consumption was the same. Don’t make sense because its been serviced every year with all genuine oils and filters and always allowed to warm up and cool down. a read on here about someone with same regen and oil consumption issues and that ended up being rings and i think his car was at 100kmiles/160000km Because these cars consume oil from new the oil must just get trapped between the rings and then sludge up over time as it cant be removed just from and oil change. Then eventually it builds up and just wears down the rings/cylinder walls causing more and more consumption to the point its an engine rebuild. I wonder if an engine flush every service on a new car that uses oil would prevent this. But still shouldnt be necessary with regular oil changes surely!

Does that mean the engines knackered? Had turbo checked and theres no oil in the intake pipes. And the pcv is ok. Car seems to run ok

Oh and one other thing. When i took it to get it check out and they replaced the o2 sensor and pressure sensor they said that it was slightly out of time and whoever fitted timing belt must of had it a tooth out. Could that be the issue? They said it wouldnt really matter.

It does use oil. Probably 0.5 litre every 1000-2000 miles. Car is on stock software. Is there anyway you can tell from the o2 sensor reading if its over fuelling?

Yes i reset values for new o2 sensor and a new pressure sensor but haven't seen any improvement. I had some one come and check everything and he says that all injectors are working fine and egr is operating as it should. He did mention that the pressure reading at idle was quite high at around 30-34mbar and the only thing he could suggest is that the dpf is just full of ash and needs either replacing or removing and having the ash removed. Did you remove your dpf from the car and gave it a proper clean? Or was it an on the car clean with a chemical that just removes the soot? my ash content is currently at 55.7g/70% the car is on 100000miles/160000km i would of thought I should be seeing more that 10-20 miles in between regens at an ash content of 70% also no matter how hard a drive the car to get the exhaust really hot it will not burn the soot off without an active regen. If the dpf didn’t look like such a pig to remove I would just take it off and get it cleaned.

Hiya. My car has the same issue. I changed lambda around 300 miles ago but still getting regens every 10-20 miles. Did the problem fix suddenly at around 1000km or gradually got better over the 1000km?

Hiya. I have the same car with the same oil consumption issue. Are you any closer to solving the issue?

Hiya cristiancci. Just wondering if you have an update on your oil consumption and frequent dpf regens? my octy consumes oil and it will do a regen around every 20 miles! After reading this im worried its piston rings but like yours, my car runs and drives fine.

My octavia vrs 2.0 tdi has started doing which seems like continues dpf regens! been watching the live data and when the soot mass reaches around 23g it will start the regen process. It then takes approximately 15 mins to go down to around 5g And regens process ends. Next time I drive the car it only take about 10 mins and soot mass rises to 23g and regen will start again and so on! oil ash content is 55g/69% did do a scan and found an intermittent o2 sensor bank 1 sensor 1 code open circuit. Deleted code and it has not returned but will be changing o2 sensor asap incase it is faulty causing it to run rich and blocking dpf at a silly rate. what should the o2 sensor be reading at idle? Mine varies from 0.004ma to 0.2 something ma any advice appreciated!