My recently bought 2016 Octavia manual diesel vRS is giving no end of problems with DPF codes being thrown up and descendng into limp mode. The story so far:

Engine management light (EML) came on coincident with switching off the stop-start function when idling in traffic on a very hot day. Checked at my indie VAG specialist in Sevenoaks with VCDS which indentified a "spurious" EGT sensor fault. Cleared using VCDS and I went on my merry way.

EML came on again about a week later which showed a fault with one ot the DPF pressure sensors which again was cleared and I went on my merry way again. Pete did show me the sensors one of which was a Bosch (probably original judging by the dirt) with the other being a Hella replacement. His advice was that there was probably a very minor discrepancy between them and they should both be renewed if the problems happened again.

EML came on again about two weeks later shortly followed by followed by the flashing curly glow plug light with car going into "limp mode". Work done was: replacement of both DPF sensors with Bosch units, replaced one of the EGT sensors between turbo and DPF which was burned away to the thickness of a pencil lead, found DPF was choked at 49 gms soot, forced regen of DPF to 4.3 gms soot and I went on my merry way a third time with the car going like a rocket ship on wheels, wallet nearly £600 lighter but which also included an oil & filter change, AC regas and cabin pollen filter change. They did tell me that fairly recently it had been fitted with a replacement turbo which was likely a DIY job because there is no record in the service history that came with it. It's likely that the engine management "electrickery" had been fooled into believing the DPF was clear when it was actually choked. This may have caused some of the original faults I had found. Sounds plausible, what does the "panel" think?

This weekend, we had to be recovered from a family wedding in Suffolk when the car went into limp mode three miles before we arrived at our hotel. Yesterday, the breakdown chappie did a code read and came up with a choked DPF and injector fault. He could not clear the DPF fault using the TOPCON code reader he had so we had to wait another 90 minutes for the flatbed to arrive.

I had topped up the oil with Castrol Edge Professional before we left home on Friday and when I checked just now it seems to have used about 300 ml in 115 miles. Bearing in mind that both my previous Octavia TDi's (2002 1.9 and 2008 2.0) hardly used any oil between changes, this seems excessive to say the least. The last previous owner was a member of a family that owns a garage chain in the Newcastle area and probably "outed" the car to auction as a bad job ASAP. I bought it in High Wycombe, from the dealer who probably bought it at auction.

My questions are:

Is it possible that a replacement (probably recon) turbo could have failed in such a way as to cause excessive oil burning and choking of the DPF?

Can anyone recommend a supplier of a) a replacement DPF and b) a replcement turbo?

The memsahib and I both love the car, as when it's running well, it's super but when it's not running well, it's a bit of a dog.....

Sorry it's a bit long-winded but to get a logical answer, as much info as possible is needed.

Thanks.

Chris.

Edited 25 August, 202525 Aug by SwallownAmazon

Eyks - high oil consumption alert. 300ml in 115 miles is extremely high. You are allowed 1 litre per 1200 miles, so your figures are way higher than that.

Suspect that either you have stuck piston rings, a blown turbo, a blocked EGR valve. The DPF will continue to get choked up with soot until you get the oil consumption under control.

I know little about turbo diesels having been brought up maintaining what are now classic cars, pre-war Morrises, Minis, Volvo Amazon, etc; is a blocked EGR valve likely to cause excessive oil consumption? I would doubt it but not sure....

The EGT error was not a P545 Error by any chance?

Mine chucks it up based on ambient temp and gives the flashing glow plug warning light appearing (and disappearing dependent on the temperate climate it annoyingly dislikes) stopping the regen.

That leads to the EML and eventually we hit the DPF warning if I ignore it for too long.

I keep a simple ODB reader in the door pocket and clear the P545 fault every so often to avoid it becoming a problem.

I think you may be on the money with a previous keeper choosing to ignore/hide the DPF issue and clogged that and then buggering things up further along into the engine.

I'd be tempted to drop the DPF and clean it off the vehicle and while you've made the space pull the EGR valve to see what condition this is in as the least expensive option.

Is the Turbo actually bad?

3 hours ago, Igol said:

Is the Turbo actually bad?

Don't know the error code for the EGT sensor I'm afraid, it was cleared down by the garage last time it was in.

My experience with two previous diesel Octavias, (2000 1.9 & 2008 2.0 Tdi) is that the engines are pretty bomb-proof so stuck rings as suggested by "varaderoguy" above are very unlikely I would have thought. Round here, the majority of taxis are Octys or Superbs, all diesel and my last TDi with the BKD engine did over 180,000 miles without missing a beat.

As to the turbo, a damaged seal seems to be the most likely cause of the excessive oil consumption; there are no discernible leaks. A new Skoda boxed turbo is £1,854.00 whereas a new one from the Garrett distributor in UK is around half that, so they tell me.

The DPF is to be "hydrocleaned" as a first job so I'll get them to check the EGR valve as well. That in itself wouldn't cause the excessive oil consumption I don't think; it may be dirty as a consequence of it.

Thanks for your input.

1 hour ago, SwallownAmazon said:

stuck rings as suggested by "varaderoguy" above are very unlikely I would have thought

No - its a thing. TDI engines can be oil burners if they aren't sympathetically run-in and regular oil changes aren't done every 10,000 miles or time-based servicing. You would need to check the bores with a borescope to confirm this though. The trouble is...this is a forum and we are responding to similar issues that we've all experienced in the past. Your original posting suggested the car is using a high level of oil and the DPF blockage is the result of the issue of the engine passing/burning oil. Doing a Hydraclean will fix the problem....for five minutes. EGR blockage will cause poor running and in the worst case, crankcase over-pressuration.

My betting is that you have a blown turbo with that high level of oil consumption. That will show up as a fault and you really need a scan done of the car for a better idea of what the car is unhappy about. Get a proper VAG specialist onto the case and get yourself a proper diagnosis.

Gentlemen,

Thanks for your input, I'm tending to the blown turbo theory as well. It's being towed up tomorrow to my garage who have looked after a variety of our Audi, Skoda and SEAT cars since 1992 when they were able to fix a problem with my company owned Audi 90 that the main dealer couldn't. They have VCDS kit to identify problems and a good old-fashioned mechanic to fix things. I'll report back when I know a bit more.

Thanks again.

There are plenty of turbo recon merchants out there who would sort a blown turbo for a fraction of the cost of new.

Even a second hand unit off ebay sent off to one for a work over would be cheap by comparison to a OEM one.

Just to put this one to bed; I got the car back yesterday after a week at my VAG specialist garage. DPF was comletely b**g***d and was replaced with a new Walker unit from Autodoc. The EGR cooler was damaged when the turbo was changed by a previous owner so was replaced; the cooler support bracket was missing so it was only supported by the physical connections to the other components. Two mounting studs were broken and had to be replaced. The oil leak was traced to a missing gasket between the engine block and the turbo bearing oil supply pipe, no need for a new turbo thank goodness. That probably explains what I thought were exhaust fumes getting into the car when the aircon was on (oil leaking onto the exhaust manifold). The second EGT sensor also was replaced so both now new. Goes like a rocket now.

Running it on VAG Spec 507 Castrol oil so I'll keep an eye on the consumption.

Altogether I've spent nearly £3,000 on this car but it will probably see me out.......

Edited 13 September, 202513 Sep by SwallownAmazon