Extremely frequent regen - every 30 kilometers

[cjperks]

I joined the forum just to add to this thread! I've not got a Seat, but my Skoda shares the engine with yours: 2.0l diesel, 184hp, CUPA engine code I think?

I've got almost exactly the same problem, 1l of oil every 1400miles (2k km) or so, regens every 70 miles or so, car has done 140k miles, 2014 build.

I've tried a few things, and nothing has made much of a difference. My next option is that I'll be pulling the DPF out and getting it flushed out as I'm REALLY trying to avoid a rebuild.

The one thing I CAN add here is an explanation for the jump in the soot level before the next regen starts. I thought it was the sensor as well, and I even went as far as buying the VCDS diagnostic cable and a new sensor to check it, and it turned out I was wrong.

There are two values the engine uses to calculate the DPF fill state, calculated and measured soot level. The VAG DPF monitoring app only looks at the calculated one, but the engine starts a regen when either hits a max value. The calculated one rises slowly, then jumps, making it look like a bad sensor, but the value from the sensor (measured) is slowly creeping up at a sensible (but high) rate in the background. I've got recorded readout to show this if anyone is bothered.

I've come across two schools of thought on this trying to solve my own problem. Oil leak is causing to DPF to fill too fast, or a near end of life DPF is causing frequent regens (which burn a bit of oil) and this causes the higher oil consumption. I also found one guy on the Briskoda forums that did his own rebuild and said that he found out that a set of engines had been made with slightly out of tolerance piston rings, leading to the problems that it seems we both have.

I'm really interested to hear if the problem goes away after the
rebuild (I hope it does!).

Im a bit late to the party here, but I hope some of this helps a bit.

 

[Rossgal]

I joined the forum just to add to this thread! I've not got a Seat, but my Skoda shares the engine with yours: 2.0l diesel, 184hp, CUPA engine code I think?

I've got almost exactly the same problem, 1l of oil every 1400miles (2k km) or so, regens every 70 miles or so, car has done 140k miles, 2014 build.

I've tried a few things, and nothing has made much of a difference. My next option is that I'll be pulling the DPF out and getting it flushed out as I'm REALLY trying to avoid a rebuild.

The one thing I CAN add here is an explanation for the jump in the soot level before the next regen starts. I thought it was the sensor as well, and I even went as far as buying the VCDS diagnostic cable and a new sensor to check it, and it turned out I was wrong.

There are two values the engine uses to calculate the DPF fill state, calculated and measured soot level. The VAG DPF monitoring app only looks at the calculated one, but the engine starts a regen when either hits a max value. The calculated one rises slowly, then jumps, making it look like a bad sensor, but the value from the sensor (measured) is slowly creeping up at a sensible (but high) rate in the background. I've got recorded readout to show this if anyone is bothered.

I've come across two schools of thought on this trying to solve my own problem. Oil leak is causing to DPF to fill too fast, or a near end of life DPF is causing frequent regens (which burn a bit of oil) and this causes the higher oil consumption. I also found one guy on the Briskoda forums that did his own rebuild and said that he found out that a set of engines had been made with slightly out of tolerance piston rings, leading to the problems that it seems we both have.

I'm really interested to hear if the problem goes away after the
rebuild (I hope it does!).

Im a bit late to the party here, but I hope some of this helps a bit.

Keep us up to date with the dpf clean, would be interesting to know

 

[BillyCool]

I joined the forum just to add to this thread! I've not got a Seat, but my Skoda shares the engine with yours: 2.0l diesel, 184hp, CUPA engine code I think?

I've got almost exactly the same problem, 1l of oil every 1400miles (2k km) or so, regens every 70 miles or so, car has done 140k miles, 2014 build.

I've tried a few things, and nothing has made much of a difference. My next option is that I'll be pulling the DPF out and getting it flushed out as I'm REALLY trying to avoid a rebuild.

The one thing I CAN add here is an explanation for the jump in the soot level before the next regen starts. I thought it was the sensor as well, and I even went as far as buying the VCDS diagnostic cable and a new sensor to check it, and it turned out I was wrong.

There are two values the engine uses to calculate the DPF fill state, calculated and measured soot level. The VAG DPF monitoring app only looks at the calculated one, but the engine starts a regen when either hits a max value. The calculated one rises slowly, then jumps, making it look like a bad sensor, but the value from the sensor (measured) is slowly creeping up at a sensible (but high) rate in the background. I've got recorded readout to show this if anyone is bothered.

I've come across two schools of thought on this trying to solve my own problem. Oil leak is causing to DPF to fill too fast, or a near end of life DPF is causing frequent regens (which burn a bit of oil) and this causes the higher oil consumption. I also found one guy on the Briskoda forums that did his own rebuild and said that he found out that a set of engines had been made with slightly out of tolerance piston rings, leading to the problems that it seems we both have.

I'm really interested to hear if the problem goes away after the
rebuild (I hope it does!).

Im a bit late to the party here, but I hope some of this helps a bit.

Thanks for the input. That's really helpful to know.

 

[BogdanB]

Any updates ? Kinda having the same issues.
Also, what would be considered a normal DPF regen interval? I've heard that around 150 miles is the average for EA288 engines.

 

[cjperks]

I'm afraid I've not got round to it yet, still trying to get my other car back on the road so that I can get this one OFF the road and pull the dpf out! I've got to line up a borrow of a car lift to get the damn thing out though, which has turned out to be, well, technically illegal until very recently...

Local garage quoted £400-500 for the work to get it out and back in. Looking at about £200 for the clean.

150 miles between regens sounds reasonable; I'm currently getting about 40.

 

[BillyCool]

My 184 has dropped to about 120 miles before regen from a fairly consistent 180 miles for the last 2 years. I do a lot of shorter journeys now so I thought that might contribute. I did a 100 mile motorway run at the weekend and it was at 65% with 120 miles gone so I thought we were doing well. 5 miles later and it's at 100% and doing a regen. It seems to have started jumping to 100% as others have reported.

I do tend to agree with the mindset that the DPF is getting full up. Mine has done 110,000 miles, so although the bottom ash is meant to be 60% or so, I don't think that means it's just over half full. I did read somewhere that 120,000 miles was about the lifespan.

It's currently not an issue but if the regen mileage starts to drop below 100 miles, I'll have to think about a DPF clean or some sort of fix.

My old Mk1 Leon with PD engine had none of this and that managed 220,000 miles with little drama!

 

[BogdanB]

And how frequent can the regens get if driving only in the city? I've recently got my DPF taken off and cleaned and trying to figure if it's within normal range. The oil consumption problem still persists though.

One thing I'm grateful for living in the Eastern part of Europe (Romania) are garage prices. About 80£ for taking it off and back on, and 70£ cleaning. Definitely worth it for this price tag, even if it's not at 100%. I was getting PERMANEMT regens. The DPF wouldn't even get to normal temperature before starting a new Regen. I've had regens run for over 90minutes when driving on the highway, which prompted the DPF warning light.

I feel you about the PD engines. My old Passat 1.9 crossed 500k Km.

 

[Vikendo]

And how frequent can the regens get if driving only in the city? I've recently got my DPF taken off and cleaned and trying to figure if it's within normal range. The oil consumption problem still persists though.

One thing I'm grateful for living in the Eastern part of Europe (Romania) are garage prices. About 80£ for taking it off and back on, and 70£ cleaning. Definitely worth it for this price tag, even if it's not at 100%. I was getting PERMANEMT regens. The DPF wouldn't even get to normal temperature before starting a new Regen. I've had regens run for over 90minutes when driving on the highway, which prompted the DPF warning light.

I feel you about the PD engines. My old Passat 1.9 crossed 500k Km.

This sounds exactly like my problem. Constant regen even on highway to the point when the DPF light comes on and I have to take a 5 minute rest with the car parked while the DPF finishes.

Unfortunately no solution from me either. I will be looking into thermostat as I heard that with faulty thermostat the temperature for successful DPF regen cant be reached. I have no idea if this might be related to that. It might indicate there is a problem with thermostat as the fans stay on almost everytime I take a trip and turn off the car. No matter how long.

At this point there are just so many problems with the car Im looking to sell it (although if this was just one big problem I might get it fixed).

If you find any new info please keep us posted. I have an intuition our cars are having the same issue.

 

[BogdanB]

To be clearer. I fixed the DPF issue. Only oil consumption remains ( and to be honest didn't really investigate it that much since I had other priorities ).
I strongly suggest that you buy a wireless OBD adapter ( such as carista for example, cheaper ones are available on AliExpress but takes time ) and buy the VAG DPF app which is a bargain and then you can check the exhaust temperature and see if it goes to at least 500 Celsius ( 600-650 being the desired range for active regens ).

The fans stay on because the car is always in an active Regen.

The DPF light turns on after being in an active Regen for 90min. The value that keeps messing your DPF is the Soot Mass Measured, that won't drop even while a regen is in progress if you are driving, since the differential pressure is too high( that's part of the equation for calculating soot mass).
When you stop the pressure is lower, and soot mass measured starts going down, completing the Regen. When you start driving again, it climbs up fast triggering another Regen.
To see that value, in the VAG DPF app go to settings and select Group 0 engines, because on the auto detect mode it will show NOX or something like that instead of Soot Mass Measured.

My DPF was indeed clogged, having a differential pressure of around 35 when idling. Now it's at 9-11 after a regen when idling.

The said oil ash volume/quantity which indicates the "lifespan" of the DPF is just an estimation and should be taken with a grain of salt. Mine was at 66% so you could say it had plenty of life left, but it wasn't the case actually.

Hope all of this sheds some light.

 

[Vikendo]

To be clearer. I fixed the DPF issue. Only oil consumption remains ( and to be honest didn't really investigate it that much since I had other priorities ).
I strongly suggest that you buy a wireless OBD adapter ( such as carista for example, cheaper ones are available on AliExpress but takes time ) and buy the VAG DPF app which is a bargain and then you can check the exhaust temperature and see if it goes to at least 500 Celsius ( 600-650 being the desired range for active regens ).

The fans stay on because the car is always in an active Regen.

The DPF light turns on after being in an active Regen for 90min. The value that keeps messing your DPF is the Soot Mass Measured, that won't drop even while a regen is in progress if you are driving, since the differential pressure is too high( that's part of the equation for calculating soot mass).
When you stop the pressure is lower, and soot mass measured starts going down, completing the Regen. When you start driving again, it climbs up fast triggering another Regen.
To see that value, in the VAG DPF app go to settings and select Group 0 engines, because on the auto detect mode it will show NOX or something like that instead of Soot Mass Measured.

My DPF was indeed clogged, having a differential pressure of around 35 when idling. Now it's at 9-11 after a regen when idling.

The said oil ash volume/quantity which indicates the "lifespan" of the DPF is just an estimation and should be taken with a grain of salt. Mine was at 66% so you could say it had plenty of life left, but it wasn't the case actually.

Hope all of this sheds some light.

Thats interesting. I didnt know the light comes on after 90 minutes of active regen.

So did getting the dpf cleaned fixed your issue? I was under impression the DPF should be fine as long as your performance isnt affected. Once its clogged you should feel it has less power. I feel like my car doesnt lack performance.

I actually has an OBD and it works with VAG DPF but I will try again to see the numbers you mentioned.

I would also blame active regen on fans but they stay on even after a short trip (5 kilometers and such) and I dont think its possible for a car to start regen after such a short distance.

If youre looking for what might be causing the oil consumption I was told by 3 separate mechanics that its probably a lose piston ring. The same thing that cjperks mentioned.

 

[BogdanB]

Strange thing is that there's no blue smoke at all.

" I dont think its possible for a car to start regen after such a short distance." - Trust me, it can. Been there The Soot Mass Measured would go up at a rate of 12-13g / KM. So it would get to 100% in 2Kms.

"So did getting the dpf cleaned fixed your issue?" - Yes, regens occur at around 300-350Kms if driving out of the city, and anywhere between 100-200 if driving in the city ( this depends on how short the trips are. It usually generates way more soot when the engine is cold ).

"I was under impression the DPF should be fine as long as your performance isnt affected. Once its clogged you should feel it has less power. I feel like my car doesnt lack performance." - Exactly my thoughts when I got the car. Performance wise it was at 100%. Perhaps this generation of engines/dpfs are more sensible to flow restrictions and thus even if the engine has enough 'breathing' room, the ECU considers the DPF to be full. I've heard that the previous family of engines, EA189, had the DPF regens at around 400-600kms.

Definetely check these values: Soot Mass Calculated, Soot Mass Measured, Differential Pressure, and also the DPF Input Gas temp vs DPF Output Gas Temp.
You can even take some screenshots in the app and post them here.

One way to tell that your DPF is clogged, and it is not burning soot ( as was my case ), the DPF Input Gas Temp. is higher than the DPF Output Gas Temp (it is normal to be higher when the regen starts, but shortly after, the Output Gas Temp should exceed the Input One). If the Output stays at around 400ish Celsius, it means that there is actually nothing burning in there.

LATER EDIT: Regarding the thermostat issue. My opinion is that a fautly thermostat in itself won't prevent the DPF from getting to the required temperature because it doesn't make any sense. The temperature in the DPF is achieved by post-injection (injecting fuel into the combustion chamber after the combustion happened, so the fuel ends up in the DPF where it gets lit). But the faulty thermostat might prevent a regen from starting, because there are some prerequisites for this to happen, like more than 1/4 of fuel in the tank and probably the engine at operating temperature<- which might be affected be the thermostat.

 

[cjperks]

I'm loving this thread and the amount of research/info that's coming together.

What kind of mileage are we talking about on everyone's engine here? Mines up at 144k miles, so I can hardly complain about the lifespan of the DPF. This is the only thing (touch wood) that seems to be wrong, apart from the usual stone chips and associated rust and bits.

@BogdanB : you'll not see the classic blue smoke as that's one of the things the DPF will soak up.


Link to the other forum thread with the piston ring info and pictures here.

 

[Vikendo]

Strange thing is that there's no blue smoke at all.

" I dont think its possible for a car to start regen after such a short distance." - Trust me, it can. Been there The Soot Mass Measured would go up at a rate of 12-13g / KM. So it would get to 100% in 2Kms.

"So did getting the dpf cleaned fixed your issue?" - Yes, regens occur at around 300-350Kms if driving out of the city, and anywhere between 100-200 if driving in the city ( this depends on how short the trips are. It usually generates way more soot when the engine is cold ).

"I was under impression the DPF should be fine as long as your performance isnt affected. Once its clogged you should feel it has less power. I feel like my car doesnt lack performance." - Exactly my thoughts when I got the car. Performance wise it was at 100%. Perhaps this generation of engines/dpfs are more sensible to flow restrictions and thus even if the engine has enough 'breathing' room, the ECU considers the DPF to be full. I've heard that the previous family of engines, EA189, had the DPF regens at around 400-600kms.

Definetely check these values: Soot Mass Calculated, Soot Mass Measured, Differential Pressure, and also the DPF Input Gas temp vs DPF Output Gas Temp.
You can even take some screenshots in the app and post them here.

One way to tell that your DPF is clogged, and it is not burning soot ( as was my case ), the DPF Input Gas Temp. is higher than the DPF Output Gas Temp (it is normal to be higher when the regen starts, but shortly after, the Output Gas Temp should exceed the Input One). If the Output stays at around 400ish Celsius, it means that there is actually nothing burning in there.

LATER EDIT: Regarding the thermostat issue. My opinion is that a fautly thermostat in itself won't prevent the DPF from getting to the required temperature because it doesn't make any sense. The temperature in the DPF is achieved by post-injection (injecting fuel into the combustion chamber after the combustion happened, so the fuel ends up in the DPF where it gets lit). But the faulty thermostat might prevent a regen from starting, because there are some prerequisites for this to happen, like more than 1/4 of fuel in the tank and probably the engine at operating temperature<- which might be affected be the thermostat.

Thank you for elaborate answer. I will be checking those things first thing tomorrow. I will try to report back.

 

[SuperV8]

My 184 has dropped to about 120 miles before regen from a fairly consistent 180 miles for the last 2 years. I do a lot of shorter journeys now so I thought that might contribute. I did a 100 mile motorway run at the weekend and it was at 65% with 120 miles gone so I thought we were doing well. 5 miles later and it's at 100% and doing a regen. It seems to have started jumping to 100% as others have reported.

I do tend to agree with the mindset that the DPF is getting full up. Mine has done 110,000 miles, so although the bottom ash is meant to be 60% or so, I don't think that means it's just over half full. I did read somewhere that 120,000 miles was about the lifespan.

It's currently not an issue but if the regen mileage starts to drop below 100 miles, I'll have to think about a DPF clean or some sort of fix.

My old Mk1 Leon with PD engine had none of this and that managed 220,000 miles with little drama!

Do you have any oil usage?

 

[SuperV8]

This is an interesting extract from the VW EA288 self study program.

https://pics.tdiclub.com/data/517/820433_EA288.pdf

See the important note regarding burning engine oil at the bottom.
This is also the reason modern Diesels need low ash oils.
If excess oil is getting into your cylinders - either past the piston rings/valve stems or past the turbo oil seal - then this will effect/shorten the life of the DPF.

 

[BillyCool]

Do you have any oil usage?

Yes - the `usual` top up after about 3,000 miles. Trying to work out if the oil use is increasing or not.

 

[BogdanB]

Yes - the `usual` top up after about 3,000 miles. Trying to work out if the oil use is increasing or not.

Most of us here would love to have only the 'usual' I guess we've got the 'special'.

 

[BillyCool]

Most of us here would love to have only the 'usual' I guess we've got the 'special'.

LOL! My DPF is deffo doing more frequent regens and I suspect that it is getting full up.

 

[BogdanB]

What's your Differential Pressure at Idle after a regen ? And also when it's close to full?

 

[BillyCool]

2 of these are from yesterday. It was at 76% (17.34g soot mass calc) then jumped up to 22.82g after another 23 miles and started a regen. The post-regen pic is from 4 weeks ago.