Extremely frequent regen - every 30 kilometers

[Vikendo]

Hello everyone, I’m really getting annoyed by this, hope someone can chime in and let me solve this.

I bought a 2015 Leon FR 2.0 TDI 135 kw. It’s got around 220k kilometers on it. One problem I have with it is constant regen of dpf. And when I say constant I mean constant.

Today it was at repair shop because of this issue and the mechanic forced the regen. It went on for about 40 minutes, mechanic said that the amount of ash went from 19.6 grams to 18 and then there is one other number which is more important and that went from 0.4 to 0.05 (please excuse my lack of knowledge, I know nothing about cars).

Later today I went for a 5 km ride and right after parking, you guessed it. It needed regen again. Now you might be wondering how I know it was regen. First of, the car has start stop system which disables itself when in regen. This was the case here, the consumption went up (0.8 l) and revs locked around 1k.

I let it run its course. Then I took another short 5 km trip, then another one and there it was again. Upon parking the icon with start stop system was disabled. This time the consumption was the same as normal (0.6 l) and revs were at 800, which is also where the car normally sits. I took a picture of this occurrence which I attached.

judging by this, you would think the problem is the way I use the car, that is only short trips. The problem is just yesterday I took a 300 km trip and the particulate filter warning showed right as I was on a highway going 140 kmh. After the icon showed up I was driving on a highway for the next 45 minutes and the regen didn’t happen at all. It didn’t happen throughout the whole 250 kilometers that I had ahead of me.

I’m not sure what’s wrong with this car, judging by the diagnostics the dpf is still fine but the frequency of regens and the times at which they happen are very odd to say the least.

i will be thankful for everyone who reads this and tries to help. Thank you!

 

[UnworthyBean]

Has the DPF ever been replaced or professionally cleaned since you've had the car?

They generally only have a fixed lifespan even if only used for long journeys. Could just be reaching its end of life.

 

[Vikendo]

Has the DPF ever been replaced or professionally cleaned since you've had the car?

They generally only have a fixed lifespan even if only used for long journeys. Could just be reaching its end of life.

never replaced or cleaned. I bought the car just now, just got first 1k km on it.

I would agree that it’s nearing its lifecycle but the mechanic today said there is no indication of the filter being filled. Even the pressure (again, no idea what pressure but he said it can be indicative of faulty dpf) was within norm.

By the way, would you recommend cleaning? I’ve read different opinions where some people say it’s pointless and others stand by its effectiveness.

 

[Crossthreaded]

If the DPF is the original, or at least been on the car a long time, it's very likely to be needing replaced. You probably know that as you drive it collects all the black soot particles until the pressure differential sensor or maybe a programmed in parameter detects that it's getting full up (sorry for untechnical language) and it will then do a regen and burn the black soot down to a grey ash which occupies a much smaller volume. I think if you are cruising on a fast road or motorway it does this without you noticing. It continues to do this until there is so much reduced ash that it starts to impede the flow of exhaust gasses. At this point you have to either remove the device and have it power cleaned to remove most of the ash deposits or fit a new one all together. I suspect this is the situation you are in. People make the mistake of believing that the regen is actually cleaning out the DPF in some way but it's not. It's just reducing the bulk down so a fine ash so more of it can be stored.

My son's Fabia Scout (1.6 CR) suffered this fate so we removed the DPF intending to have it cleaned but, luckily, we gave it a very close examination first and found multiple wee stress cracks on the pipes. We welded it all up when we found out what a new one cost and shortly afterwards he traded it in for a Kia! (7 year warranty)

 

[BillyCool]

Buy this:

Carista OBD2 Bluetooth Adapter and App: Diagnose, Customize and Service your VW, Audi, SEAT, Skoda, Nissan, Infiniti, Toyota, Lexus, BMW, Mini: Amazon.co.uk: Car & Motorbike

Buy Carista OBD2 Bluetooth Adapter and App: Diagnose, Customize and Service your VW, Audi, SEAT, Skoda, Nissan, Infiniti, Toyota, Lexus, BMW, Mini at Amazon UK. Free delivery on eligible orders.

www.amazon.co.uk

And get this app on your phone:

VAG DPF – Apps on Google Play

DPF particulate filter status of your TDI VW Audi Seat Skoda (see engine list)

play.google.com

This will allow you to get real time monitoring of your DPF, when it regens, soot/ash levels and we can then see if anything isn't quite right.

This is a screenshot of VAG DPF when the car is running normally and not doing a regen.

2 of the figures to look at.

Soot mass calc - this tells you how much soot is in your DPF. This increases as you drive the car. When it reaches a certain trigger point, the car starts a regen. On my car, this is 23.37g of soot. VAG DPF displays this as a % to help you know when a regen is due. So at roughly 95%, it starts a regen.

The regen will burn that soot off and that figure will drop down to about 5g and then stop. On my car that is about 23%. It never goes all the way to zero.

Every regen produces oil ash residue. This stays in your DPF forever and effectively determines the life of your DPF. On this screenshot it is 41.2g or 52%. That means that my DPF is effectively half way through it's life (disclaimer - this does not mean that the DPF will last until `100%` - it may become unusuable before that). This figure is a good guide of the health of your DPF. My car has done 104,076 miles (167,494km) at that figure.

I think that your mechanic meant that your soot mass calc dropped from 19.6 to 18 grams. If that is for a 40 mins forced regen then something isn't right. A regen should last maybe 20 mins and be completed and not drop by 1 gram in 40 mins.

On some car diagnostic tools, they report the oil ash residue in litres, so my car was 0.06 but that was quite a while ago using garage diagnostics and I can't give an accurate figure now. That is why your mechanic mentioned the rise from 0.4 to 0.5. Based on that figure, your DPF doesn't sound full up with oil ash (a good thing). It doesn't seem to be completing a regen properly. I can't be sure as I'm only going on what you've said.

The other figures tell you how many miles since last regen etc.

With that information, you can start to understand:

1. Is my DPF performing normally (we don't think it is)
2. Is it near end of life? (possibly but 0.06 suggests not)
3. What is causing the constant regens (we don't know yet)

There are lots of sensors on cars that need to be working to allow a proper regen and this may be a sign of another issue with the car.

I had a carbon engine clean, just to see what one did and the car had done 80,000 miles at the time. The best part was the diagnostics. The mechanic checks fuel flow, temp senders etc, a lot of things that influence the DPF and regens. It only takes something like your thermostat to be faulty and stop the car getting up temperature and it won't (can't) do a regen.

VAG DPF might not tell you what the problem is, but it will give you some helpful data to understand where to look.

Carista is £25/€30 and the app isn't that much. It's well worth it.

And get inCarDoc Pro as well. You can check your coolant temps. Don't trust the car, anything from 75 to 100 degrees always reads as 90. You need more accurate readings.

Something isn't right and if you get a bit more data regarding your DPF it might help.

 

[Crossthreaded]

Thank you Brian, what an interesting post - I really enjoyed reading it and, although we now only have one diesel (of the 6 cars I look after) in the "family fleet" - and it's the Kia so still under warranty for several years yet - You've given me some research to do.

 

[Vikendo]

Thank you for taking the time to reply to my question guys. I will definitely be looking into this further but so far it seems the problem will be somewhere else, not necessarily with the dpf filter itself.

The fact that it says Engine needs to be running (which should mean the regen is in process) while the revs are around 800 and consumption is 0.6 l probably means something is wrong.

 

[ryanfilips]

Hello guys, i have the exact same problem. My car is 2014 Leon 2.0L Diesel 184 FR. Brilliant car altogether apart form this "LITTLE" issue with the DPF.

@Vikendo first, many reasons could be stopping the auto start/stop system from turning the engine off, lets say if the car is stopped on a downhill or uphill, or not straight and so much more, mine isnt working sometimes without doing dpf regen.

@Brian Gordon-Stables thanks for the brilliant post m8, i already have the Carista adapted, will get the app now and do some tests tomorrow.

Now to the actual problem. Im mostly doing in town miles, 20-30% motorway at max, occasionally car is taken on a long trip. Got the car 2.5 years ago on 59k miles, its done 108k now. At first it was doing a regen every other day at around 120 miles done in-between regenerations. Some time after it started doing it every day. Then sometimes twice a day, to get to the point now where it does it every 20 miles, with my driving thats 3-5 regens a day. It is very annoying. Car always drank Shell normal / vpower fuel, serviced, oil changed on time with good brands oil and everything as it should be. This summer after an oil change it developed another problem : higher oil consumption.....

Went to so many garages, some certified VW specialists, had the differential pressure sensor replaced, just because the original part was superseded by VW, used so many fuel additives, had a forced regeneration done, software update, all to no avail.....

Havent tried carbon clean tho or any other proper cleaning of the dpf, how did yours go Brian, was it any good ?

Some of the places ive been to suggest that engine oil might me leaking from piston rings or turbo and gets trapped into the DPF and blocks it, some other say that due to too frequent regenerations car is using too much oil....go figure

One very strange thing is that after a regen it goes down to about 5 grams as u say, and then starts building back up of course, gets to about 8-9-10 grams and then instantly jumps to 23-24-25 and a few seconds after a regeneration starts.....never ever it had gone all the way up to 20+ grams by itself, always jumps up.....
But i only have the Carista software and one called Torque pro, they dont give me much insight on the dpf itself, but i will try this VAG dpf tomorrow and let u guys know what i can find out.

 

[BillyCool]

Hello guys, i have the exact same problem. My car is 2014 Leon 2.0L Diesel 184 FR. Brilliant car altogether apart form this "LITTLE" issue with the DPF.

@Vikendo first, many reasons could be stopping the auto start/stop system from turning the engine off, lets say if the car is stopped on a downhill or uphill, or not straight and so much more, mine isnt working sometimes without doing dpf regen.

@Brian Gordon-Stables thanks for the brilliant post m8, i already have the Carista adapted, will get the app now and do some tests tomorrow.

Now to the actual problem. Im mostly doing in town miles, 20-30% motorway at max, occasionally car is taken on a long trip. Got the car 2.5 years ago on 59k miles, its done 108k now. At first it was doing a regen every other day at around 120 miles done in-between regenerations. Some time after it started doing it every day. Then sometimes twice a day, to get to the point now where it does it every 20 miles, with my driving thats 3-5 regens a day. It is very annoying. Car always drank Shell normal / vpower fuel, serviced, oil changed on time with good brands oil and everything as it should be. This summer after an oil change it developed another problem : higher oil consumption.....

Went to so many garages, some certified VW specialists, had the differential pressure sensor replaced, just because the original part was superseded by VW, used so many fuel additives, had a forced regeneration done, software update, all to no avail.....

Havent tried carbon clean tho or any other proper cleaning of the dpf, how did yours go Brian, was it any good ?

Some of the places ive been to suggest that engine oil might me leaking from piston rings or turbo and gets trapped into the DPF and blocks it, some other say that due to too frequent regenerations car is using too much oil....go figure

One very strange thing is that after a regen it goes down to about 5 grams as u say, and then starts building back up of course, gets to about 8-9-10 grams and then instantly jumps to 23-24-25 and a few seconds after a regeneration starts.....never ever it had gone all the way up to 20+ grams by itself, always jumps up.....
But i only have the Carista software and one called Torque pro, they dont give me much insight on the dpf itself, but i will try this VAG dpf tomorrow and let u guys know what i can find out.

Hi @ryanfilips.

Sorry to hear you've got similar issues.

I was reading your post and trying to get an idea of what could be wrong. Your last comment about the soot level jumping up made me think it was a faulty differential pressure sensor but you've already had that replaced. This is still an interesting article about and it suggests a blocked pipe in/around the sensor might be worth exploring. Something is making the car think the soot levels have shot up when they probably haven't.

Making sense of your sensors: DPF differential pressure sensor

To understand how the DPF differential pressure sensor works, why it fails, and how to replace it when it does, let’s briefly discuss the DPF.

www.delphiautoparts.com

Obviously the car should not be doing a regen that often and the jump in soot levels is clearly triggering that (as it should). We just need to work out why.

To try and cover off some of your other comments.

Higher oil comsumption - more regular regens can use more oil. Mine needs topping up every once in a while. Yours is probably using a lot due to the current situation.

Carbon clean - this is a whole subject by itself. Some people say it's snake oil and has no benefit. Others say it does something. I'm in the latter camp. Firstly, a carbon clean has nothing to do with your DPF. The CC is supposed to help clean out the crud etc from a higher mileage car and help it run a bit cleaner/smoother. This should, in essence, be better for your DPF. There are several CC methods, some use chemicals, some do not. Some are sh!te, some are not.It can be a bit of a minefield

The guy I used knows his stuff. Good with cars, clearly loves what he does and very knowledgeable. I got the clean done as the car was on 80,000 miles and for £100 I wanted to see if it did much. The plus side was that he also plugs in his diagnostic tool and checks fault codes and loads of other data. If the car has other issues, he won't even do the carbon clean and will tell you what to sort out before he comes back to do the CC.

So - I got some decent diagnostics (all was well) and a CC. The results of the CC? I was told the car was pretty healthy anyway but it helped with the idle and the pick up was better. It's all subjective but I thought it was worth it. For £100 I got the clean and about £80 worth of diagnostics (if you're into that sort of thing he'll happily talk through it all and show you. I'm pretty sure he also emailed me the results.)

The one thing he did say to me was - if the DPF was having issues, a DPF clean is pointless. You clean the DPF, the same issues persist and you end up back where you started and a few £££'s lighter. You need to sort the root cause first.

If you can post a screenshot of your VAG DPF figures that would be interesting to see.

I still think it could be something to do with the sensor. The tubes that they suck the air through can get blocked and even a brand new sensor will give incorrect readings. Do you know if these were checked? I have also read that some `new` sensors have failed. Was yours genuine part? Is it running VAG 507.00 oil?

EDIT - I didn't know this but apparently the DPF pressure sensor is on the top of the engine. I always thought it was underneath. Might be worth having a look.

 

[ryanfilips]

Thank u very much man for the very detailed and fast response. For the oil, no I've only used Castrol and she'll, but tbh with u when it started using more oil this summer was topping up with whatever I had, same specification but not a good brand, not having it for long tho as I'm changing oil rather often.
I will have a look at the sensor later on or tomorrow and try to figure something out.


As for the app it's brilliant, many thanks I will upload some screenshots now. Had a fuel light this morning, so a regen can't start, as soon as I refueled it ramped the soot up to 100% + 19% on top u will see on the screenshot.

First one just before refuel, second just after, jumps instantly to over 100%, third after the regen and u can see on it differential pressure being 26 hpa when stationary, don't know if that's good or still outside of the normal chart

 

[Vikendo]

Hello guys, i have the exact same problem. My car is 2014 Leon 2.0L Diesel 184 FR. Brilliant car altogether apart form this "LITTLE" issue with the DPF.

@Vikendo first, many reasons could be stopping the auto start/stop system from turning the engine off, lets say if the car is stopped on a downhill or uphill, or not straight and so much more, mine isnt working sometimes without doing dpf regen.

@Brian Gordon-Stables thanks for the brilliant post m8, i already have the Carista adapted, will get the app now and do some tests tomorrow.

Now to the actual problem. Im mostly doing in town miles, 20-30% motorway at max, occasionally car is taken on a long trip. Got the car 2.5 years ago on 59k miles, its done 108k now. At first it was doing a regen every other day at around 120 miles done in-between regenerations. Some time after it started doing it every day. Then sometimes twice a day, to get to the point now where it does it every 20 miles, with my driving thats 3-5 regens a day. It is very annoying. Car always drank Shell normal / vpower fuel, serviced, oil changed on time with good brands oil and everything as it should be. This summer after an oil change it developed another problem : higher oil consumption.....

Went to so many garages, some certified VW specialists, had the differential pressure sensor replaced, just because the original part was superseded by VW, used so many fuel additives, had a forced regeneration done, software update, all to no avail.....

Havent tried carbon clean tho or any other proper cleaning of the dpf, how did yours go Brian, was it any good ?

Some of the places ive been to suggest that engine oil might me leaking from piston rings or turbo and gets trapped into the DPF and blocks it, some other say that due to too frequent regenerations car is using too much oil....go figure

One very strange thing is that after a regen it goes down to about 5 grams as u say, and then starts building back up of course, gets to about 8-9-10 grams and then instantly jumps to 23-24-25 and a few seconds after a regeneration starts.....never ever it had gone all the way up to 20+ grams by itself, always jumps up.....
But i only have the Carista software and one called Torque pro, they dont give me much insight on the dpf itself, but i will try this VAG dpf tomorrow and let u guys know what i can find out.

I know about other things that might interfere with start-stop system but trust me. This one is definitely a dpf regen.

Im still looking for the culprit. Ive been to three diagnostics so far (one seat and two non-seat) and two of the three agreed it might be a faulty turbo (one of them was seat). Im having the turbo checked on friday so I will let you know how it went. They will check to see if repass might be neccessary. I was told this is the most possible cause for high oil consumption and constant regen. Just yesterday I had to stop on the highway for a top up. And that is 1k kms after an oil change. I had to use about 1 liter of it. So in my case the usage is quite high - 1l every 1k kms. I really hope the frequent regen is because of high oil usage and new turbo can solve this.

 

[ryanfilips]

Wow, sounds expensive tho, a new turbo, but if that solves two problems at the same time I guess it's worth it. No one ever had suggested to me that it would be the turbo, some said piston rings for the high oil usage, others said regenerations themselves burn oil, don't know but sounds very probable, please do let us know tomorrow how it goes ?

P.s. I always thought a faulty turbo makes winning noises, mine has no noise coming from it whatsoever. But I did notice something that wasn't there before, when the regen starts white smoke is coming out of the exhaust, and for the first few mins it smells as burnt oil....

 

[BillyCool]

Thank u very much man for the very detailed and fast response. For the oil, no I've only used Castrol and she'll, but tbh with u when it started using more oil this summer was topping up with whatever I had, same specification but not a good brand, not having it for long tho as I'm changing oil rather often.
I will have a look at the sensor later on or tomorrow and try to figure something out.


As for the app it's brilliant, many thanks I will upload some screenshots now. Had a fuel light this morning, so a regen can't start, as soon as I refueled it ramped the soot up to 100% + 19% on top u will see on the screenshot.

First one just before refuel, second just after, jumps instantly to over 100%, third after the regen and u can see on it differential pressure being 26 hpa when stationary, don't know if that's good or still outside of the normal chart

Clearly somethings not right. You're going from a `clean` DPF to full instantly. To me, that's a dodgy sensor and/or blocked sensor pipes. I can't see why a turbo, EGR, piston rings or any other issue can cause the readings to spike so much. It's also the cheaper fix.

If a car does an active regen, it can smell a bit acrid but not sure about the white smoke? You could have more than one issue, it's hard to tell.

As for the differential pressure, I don't know if that's good or bad. I'll have a look at mine.

I read somewhere else that an issue with the ECU can cause erroneous DPF figures as well. I always like to start small and build up. Personally, I'd take the DPF sensor off and blow some compressed air through the 2 pipes. I think that if you have VCDS you can check the air flow through the sensor and see if anything is amiss. Then change the sensor (again). If you know the engine ECU is getting dodgy data you know where to start.

If that is all fine then you'll have to start writing a list!

 

[ryanfilips]

Thanks for your advices.
I tried cleaning the differential pressure sensor's hoses today, and for my surprise, there's only one hose attached to it..., The second connection is empty....very weird

 

[BillyCool]

Thanks for your advices.
I tried cleaning the differential pressure sensor's hoses today, and for my surprise, there's only one hose attached to it..., The second connection is empty....very weird

I have the same car as you and just checked mine and it's the same set-up. I don't know enough about them to know how it all works.

 

[ryanfilips]

So yours is just one hose as well ? I've read online somewhere that there are supposed to be two of them, no checks pressure before the DPF the other one after and it calculates the difference to "measure" the content of the DPF, everywhere I've read about differential pressure sensors they all refer to two hoses....

 

[BillyCool]

So yours is just one hose as well ? I've read online somewhere that there are supposed to be two of them, no checks pressure before the DPF the other one after and it calculates the difference to "measure" the content of the DPF, everywhere I've read about differential pressure sensors they all refer to two hoses....

I thought that as well but have a read of this:

Is this pressure sensor missing a pipe?

Hi all. Got a replacement dpf pressure sensor today.. and before I code it ( I understand its one chance to code it / adapt it and it cant be re adapted) I want to make sure Im not missing a pipe... It doesnt look right. Found a diagram online that suggests I should have 2 pipes off the sensor.. ...

www.briskoda.net

It seems that a new set-up only use 1 pipe. There are some schematics that are helpful.

Also - on page 3 - some guy mentions the same problem you have and it seems that it can be either /or:

• Bad sensor - a new ones needs to be coded/calibrated apparently
• Issue with ECU updates
• Possible EGR blockage

They say that the white smoke is possibly unburnt fuel.

Have a look at is and see if any of it helps.

 

[Vikendo]

Wow, sounds expensive tho, a new turbo, but if that solves two problems at the same time I guess it's worth it. No one ever had suggested to me that it would be the turbo, some said piston rings for the high oil usage, others said regenerations themselves burn oil, don't know but sounds very probable, please do let us know tomorrow how it goes ?

P.s. I always thought a faulty turbo makes winning noises, mine has no noise coming from it whatsoever. But I did notice something that wasn't there before, when the regen starts white smoke is coming out of the exhaust, and for the first few mins it smells as burnt oil....

I had the turbo checked and it is moving a tiny bit, but the mechanic said this alone cant be causing the 1 liter/1k km oil consumption. No whining here either so Im ruling out the turbo. For now.

What I am getting is new piston rings, head gasket, valve seals, basically everything that is related to oil consumption. Its not going to be cheap but I pray to god this is going to fix the issue of high oil consumption as well as the frequent DPF regen as I believe a lot of oil is ending up in the filter and this is causing the regen to be this frequent. Definitely let me know if you have some news on your side, I will be probably posting a new thread asking for help regarding the oil consumption.

 

[Rossgal]

I had the turbo checked and it is moving a tiny bit, but the mechanic said this alone cant be causing the 1 liter/1k km oil consumption. No whining here either so Im ruling out the turbo. For now.

What I am getting is new piston rings, head gasket, valve seals, basically everything that is related to oil consumption. Its not going to be cheap but I pray to god this is going to fix the issue of high oil consumption as well as the frequent DPF regen as I believe a lot of oil is ending up in the filter and this is causing the regen to be this frequent. Definitely let me know if you have some news on your side, I will be probably posting a new thread asking for help regarding the oil consumption.

WOW! an engine rebuild seems extreme to solve a regen issue, never mind expensive! My car has an issue using oil, but as yet I haven't had the DPF checked

 

[Butty]

Think you've answered your own question! A large 1 litre/ 1,000 km oil leak ending up in the DPF isn't good news.