Skoda Octavia vrs 2014 130,000 miles

runs ok when cold untill temp gets to normal then revs sit at 10,000 stop start does not operate high fuel consumption fans always running when switch off engine 

it only drives normal when on reserve fuel when fuel is added the DPF symbol comes on then goes of after next time engine is restarted 

any ideas ?

 

It sounds like the engine isn't being allowed to finish running a DPF clean cycle. When the DPF clean cycle runs the engine revs will be high to get the DPF filter hot enough to burn off the carbon deposits, if the filter clean fails repeatedly (if you stop the engine while its running) it will try and do another DPF clean.

If you can just let the engine finish its DPF clean cycle, yes the engine will rev high and it might smell hot but it needs to do this. Sometimes taking it up the motorway for a blast for about 30 miles, leave the car in 4th or 5th gear and drive it at 70 mph, I know this sounds totally wrong but it might be the only way for the DPF clean cycle to run.

Have had force gen done the drive this is a constant problem I do nearly 1000 miles a month no smoke no lights no limp mode I think it might be the DPF temp sensor ?

130k miles is where a few stating end of life for the dpf.  Do you have the ability to scan the car or get someone to investigate the dpf.  Sounds to me like a new one is needed.

12k miles /year isn't huge mileage.  What sort of miles are they?  Town, stop/start, motorway?

12 hours ago, StriderDog said:

It sounds like the engine isn't being allowed to finish running a DPF clean cycle. When the DPF clean cycle runs the engine revs will be high to get the DPF filter hot enough to burn off the carbon deposits, if the filter clean fails repeatedly (if you stop the engine while its running) it will try and do another DPF clean.

If you can just let the engine finish its DPF clean cycle, yes the engine will rev high and it might smell hot but it needs to do this. Sometimes taking it up the motorway for a blast for about 30 miles, leave the car in 4th or 5th gear and drive it at 70 mph, I know this sounds totally wrong but it might be the only way for the DPF clean cycle to run.

Sounds like this to me too.

2 hours ago, MarkyG82 said:

130k miles is where a few stating end of life for the dpf.  Do you have the ability to scan the car or get someone to investigate the dpf.  Sounds to me like a new one is needed.

To me 130K seems a bit too soon for DPF end of life, but scanning the car to investigate is definitely a good idea. If you already have a suitable Android phone or tablet, you can get an app called VAG DPF which supports most VW Group diesel engines for £3.30 (limited version f.o.c.) and a bluetooth diagnostic connector for around £20 or less. There is an example on this thread which suggests that the DPF should be good for 200K miles, and I have obtained a similar figure for my own car: https://www.briskoda.net/forums/topic/476704-our-octavia/

 

1 minute ago, OldBoyScout said:

Sounds like this to me too.

To me 130K seems a bit too soon for DPF end of life, .........  There is an example on this thread which suggests that the DPF should be good for 200K miles, and I have obtained a similar figure for my own car: https://www.briskoda.net/forums/topic/476704-our-octavia/

 

 

But, If it has been driven with lots of short trips with stop/start enabled for most of its life and not allowed to be regenned correctly, 130k could well be life.  I need to check mine but, like you,  I expect to be closer 200k before I have to replace it (or the car).

21 minutes ago, MarkyG82 said:

But, If it has been driven with lots of short trips with stop/start enabled for most of its life and not allowed to be regenned correctly, 130k could well be life.  I need to check mine but, like you,  I expect to be closer 200k before I have to replace it (or the car).

The figure of 200K miles is a projection based on the amount of ash in the DPF, the ash being what is left after soot is burned away by the regen processes. I am thinking that soot left in the system due to incomplete regens in the past will not be a serious problem provided that a regen is allowed to complete in the future before the DPF becomes badly blocked. The level of ash is most critical, as it cannot be removed or reduced by a regen.

 

Rather than start a new thread I am going to piggyback my question re DPF behaviour.

 

I had assumed that the engine had to be at operating temperature for a regen, is that correct?

 

I ask because my Yeti is not yet on the road and has been repeatedly started for short periods, often left to run till oil temp up to recharge the battery. The other day I started it from cold, moved it back & forth while shunting cars & then drove round the block, a couple of hundred yards, engine still stone cold, left it idling when parked to charge battery & noticed the coooling fans were on, a regen? It was at 1000 rpm but may have been anyway during the warm up period?

 

Once hot I saw that the fans were no longer running (dont know when they stopped) but still at 1000 rpm, a blip of the throttle and it was at 800rpm approx.

 

So was it a regen or if not why were the fans running?

 

Checked the oil or ash level with VCDS (can never recall which is which) and it showed 3g IIRC against a calculated 33g, was suspicious of the other reading (oil volume?) the one measured in litres as it showed exactly the same figure (0.9 or 0.09l) as my neighbours F/L Octavia.

24 minutes ago, J.R. said:

I had assumed that the engine had to be at operating temperature for a regen, is that correct?

 

My understanding is that an active regen is triggered when the soot level reaches 45% and the other conditions are favourable. I would guess that includes operating temperature. I was once surprised when I found that my car had started a regen just a couple of miles after setting out. I was just driving slowly through town mainly in 20mph limits, and noticed the engine idling at about 1200 rpm when I stopped at traffic lights.

 

I think you may be looking at the oil ash level which shows the residue from the soot that has been burned in the lifetime of the DPF, and this will gradually increase over time, whereas what relates to the timing of a regen is the level of soot before it has been burned away by the regen process.

 

I don't know enough to say whether or not it was a regen or why the fans may have been running, but I wouldn't be too concerned either way. Once you get the car properly up and running the car should be able to take care of the regens by itself. Until then I don't expect the condition of the DPF will change very much.