DPF light on every 2 weeks

[Nathan Grimes]

Hi,

I wonder if anyone might be able to help with a diesel particulate filter problem on my Audi A3 2.0 Tdi Black edition, 11 plate. It has done 117,000 miles and I got it in October last year. Since then, the dpf light has been coming on every 2 weeks. Each time the light illuminates I take it on the motorway in 4th or 5th gear and the car regenerates and the light goes off within about 15 minutes. However, around 2 weeks later it comes back on and I need to get back on the motorway.

To be fair I mostly do town driving, short journeys and maybe a bit further at weekends when I take the family out but still generally less than 10 miles. I realise this type of driving better suits a petrol but my last car was a diesel and I never had any DPF issues (perhaps it didn't have one) and I wasn't aware of potential DPF issues before I bought the A3.

The car was last serviced in July 19. Just Oil and filter change. I've had the fault codes read and only one fault was returned and that was with the Gearbox Neutral Position Sensor (which is probably why my start/stop isn't working, but anyway that's a separate issue and one i'm not too bothered about!).
I guess the car isn't getting a chance to regenerate with the start stop short journeys that I do but when the light does illuminate I can force the regeneration by driving at 3000rpm for 10-20 mins so the car is able to regenerate.

Is this normal behaviour or is there something going on here?
What are the next steps in diagnosing any issue? A garage I went to recommended a Force Regen and then a Full service at a cost of £350 but there's no guarantee that would solve the problem. If it didn't, they recommended a DPF clean with fluids injected at a cost of £300.
I've been using Shell V Power diesel for the last full tank and a half.

Any advice would be great! Thanks,

Nathan

 

[NHN]

Force regens, check soot levels, although, eventually it will clog beyond regen & require cleaning out.

You could get the required software etc & do regens yourself given town driving, it's just a byproduct unfortunately of the driving type.

Full service won't help the dpf imho, it's the type of driving that'll make an impact.

 

[Nathan Grimes]

Thanks for your reply.

When I had the codes read last week he said the Soot/Ash level was 9.29 which he seemed to think was quite low. But I had regenned it on the motorway a few days before that.
I find it surprising that the soot levels can get to a point where the DPF light illuminates within a couple of weeks, even with my style of driving.

So would a force regen be more effective than me taking it on the motorway in 4th/5th gear for 20 minutes?

 

[Nathan Grimes]

Also I did check the oil level the other day and it did look way too high, looked well overfilled to me but wondering if that could be Diesel mixed in with the oil as a result of all the regens?! Could that be having an effect?

 

[NHN]

9.29 is low tbh, you ideally need to monitor with some diag tool as it maybe a sensor is playing up.

Oil level high is also a possible symptom of clogged dpf.

Based on the oil I'd consider the dpf sensor/s being checked as that percentage seems low for these issues.

 

[LEE69]

The DPF is at the end of its useful life at that mileage. You either replace it or get it removed and a software patch added. If it's done properly mot won't be a concern

 

[NHN]

The DPF is at the end of its useful life at that mileage. You either replace it or get it removed and a software patch added. If it's done properly mot won't be a concern

Not necessarily true, friend has the same car, more miles, dpf was at 40-50 which is impossible to regen, had it cleaned & now runs perfectly, so it's possible to resolve without new dpf it removal, although it's case by case basis.

 

[LEE69]

Just going by what a friend says (tuner) deals with this all the time

 

[NHN]

Appreciated, as I said, case by case basis.

Fact it's illegal to remove isn't helping people with these issues.

 

[Nathan Grimes]

Wouldn't a dodgy sensor have shown up as a fault code on the diagnostics machine?
Hoping the DPF isn't at its end of life! Understand they aren't cheap at all!

 

[NHN]

Wouldn't a dodgy sensor have shown up as a fault code on the diagnostics machine?
Hoping the DPF isn't at its end of life! Understand they aren't cheap at all!

Not necessarily, given your oils high & dpf is showing low soot levels, I'd look at sensors 1st as regen this often with low level seems weird.

 

[Nathan Grimes]

Ok thanks. I'll see if I can get a garage to test the sensors as a next port of call.
When your friend had his cleaned, was that a proper clean with the DPF taken out or a clean with fluids with the DPF still in, like a Terraclean type service?
All of the DPF clean services around here (Exeter, Devon) seem to be fluids injected without physically taking the DPF out.

 

[NHN]

Not sure which, but it worked, removing dpf is labour intensive tbh so if it's cheap, you can bet it's liquid injected to break down the insides.

 

[Bloxham]

You might be able to find a garage with a DPF cleaning machine, I know a local garage where I get MOTs done has got one. If you've checked the temp and pressure sensors on the DPF are OK, you could try that next.
If you know the engine oil level is too high, I would suggest an oil change ASAP, fill to no more than half way up the dipstick then monitor.

 

[Retroman]

The car should conduct "activated regens" long before the warning light comes on. My car is at 100,000+ and I've never had the warning light come on and I do around 7,000 miles pa mixed driving. DPFs eventually get clogged with residual ash which cannot be removed by additives or other conventional treatments designed to clear carbon. Personally, I would change the oil and get it to the correct level (mine holds about 4.25 litres) and get the sensors checked which monitor and activate a regen. Is it possible that a previous owner has tampered with the "mapping" to map out the EGR whilst leaving the DPF in situ? This would have the impact of producing a lot of carbon for the DPF to deal with.

 

[Nathan Grimes]

Thanks all.
I've just been to a Bosch service centre who specialise in Diesels and they've offered to test the sensors and diagnose the issue. £72 +vat just to diagnose though which sounds quite high to me.
They said the would normally come on every 300-400 miles or so but I'm not getting near that mileage in the 2 weeks between it going off and coming on.
They do offer DPF clean with fluids and will also remove the DPF and physically clean it if necessary.
Think I might take it to them next week.

 

[Nathan Grimes]

The car should conduct "activated regens" long before the warning light comes on. My car is at 100,000+ and I've never had the warning light come on and I do around 7,000 miles pa mixed driving. DPFs eventually get clogged with residual ash which cannot be removed by additives or other conventional treatments designed to clear carbon. Personally, I would change the oil and get it to the correct level (mine holds about 4.25 litres) and get the sensors checked which monitor and activate a regen. Is it possible that a previous owner has tampered with the "mapping" to map out the EGR whilst leaving the DPF in situ? This would have the impact of producing a lot of carbon for the DPF to deal with.

I have no idea if the EGR could have been mapped out. I would have thought the fault code reading diagnostics would have flagged something EGR related if so?

 

[Retroman]

Mine does an "activated" regen around every 300/400 miles if I don't manage to get in any longer trips to do "automatic regens". However, this doesn't trigger the warning light. I have a friend with a new Merc and his does similar. The warning light denotes minimum 55% soot/carbon loading. To produce this much soot/carbon in 300/400 miles is not usual - hence my suggestion above.

 

[Nathan Grimes]

Mine does an "activated" regen around every 300/400 miles if I don't manage to get in any longer trips to do "automatic regens". However, this doesn't trigger the warning light. I have a friend with a new Merc and his does similar. The warning light denotes minimum 55% soot/carbon loading. To produce this much soot/carbon in 300/400 miles is not usual - hence my suggestion above.

Ok thanks for your suggestion I'll get that looked at also.
What about the incorrect oil? Could that cause the DPF to clog far quicker? I haven't changed the oil since I got the car in October so I don't know what the previous owner has put in it. I just assumed it would be ok as it was serviced in July.

 

[Retroman]

A cheap oil might produce more carbon via its recycled vapours etc, although I would doubt it would cause extreme "carbonisation" over a short term. The VAG spec is C3 (low ash) with the 504/507 approval. I use this. My car runs very smoothly and burns none between annual services.

https://www.ebay.co.uk/itm/Quantum-...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

 

[Nathan Grimes]

Update: just been out and there was no dpf light but the glow plug light is flashing and the emissions light is constantly on. Both amber. This hasn't happened before. Feels like turbo has gone as I've got a big loss of power. Am I in limp mode?
Could a sensor have failed or something? Or egr valve? Considering the problems I've been having with the dpf light coming on every 2 weeks, it feels like this is the end result and something has gone. What do you think?

 

[Bloxham]

You need to plug into VCDS. EGR valve faults will cause limp-mode, usually reset short-term by switching off then on again.
I right pain to change the EGR valve on these, but could be worse, at least it's not a quattro.
Definitely don't start changing parts without a proper diagnosis first, unless you want to throw money away.

Totally agree with Retroman on the oil - Quantum Longlife 3 is perfect for these TDi and cheap on eBay - I use it in all VAG cars.

 

[Bloxham]

As said above, it's not normal to get any warning lights every 200-300 miles - find another garage !

 

[Nathan Grimes]

You need to plug into VCDS. EGR valve faults will cause limp-mode, usually reset short-term by switching off then on again.
I right pain to change the EGR valve on these, but could be worse, at least it's not a quattro.
Definitely don't start changing parts without a proper diagnosis first, unless you want to throw money away.

Totally agree with Retroman on the oil - Quantum Longlife 3 is perfect for these TDi and cheap on eBay - I use it in all VAG cars.

Thanks. Just been out in it and it's not in limp mode anymore. But the dpf light came on again! That's 2 weeks to the day and I've only covered about 50/60 miles in that time! Took it on an A road in 4th gear and the dpf light cleared within about 5 minutes. But the emission control system light (looks like engine management to me but the manual says emission control) is still illuminated.
Is driving fine though.
Shame there is nobody on the vcds map near me. Will take it to another garage tomorrow. £40 to read the codes which doesn't seem too bad.

 

[Nathan Grimes]

Thanks. Just been out in it and it's not in limp mode anymore. But the dpf light came on again! That's 2 weeks to the day and I've only covered about 50/60 miles in that time! Took it on an A road in 4th gear and the dpf light cleared within about 5 minutes. But the emission control system light (looks like engine management to me but the manual says emission control) is still illuminated.
Is driving fine though.
Shame there is nobody on the vcds map near me. Will take it to another garage tomorrow. £40 to read the codes which doesn't seem too bad.

So I got a mobile mechanic to read the codes but it just said 'malfunction' next to the engine control system line. He said the engine management light probably came on due to the dpf issues I've been having so he proceeded to clear the codes without me knowing the reason for the EML being triggered. So I'm none the wiser!
Booking it in for an oil and filter change this week so hopefully that will help. Also need to get the dpf sensors properly tested. Beginning to wish I got a petrol!

 

[ab1702]

Hi,

I wonder if anyone might be able to help with a diesel particulate filter problem on my Audi A3 2.0 Tdi Black edition, 11 plate. It has done 117,000 miles and I got it in October last year. Since then, the dpf light has been coming on every 2 weeks. Each time the light illuminates I take it on the motorway in 4th or 5th gear and the car regenerates and the light goes off within about 15 minutes. However, around 2 weeks later it comes back on and I need to get back on the motorway.

To be fair I mostly do town driving, short journeys and maybe a bit further at weekends when I take the family out but still generally less than 10 miles. I realise this type of driving better suits a petrol but my last car was a diesel and I never had any DPF issues (perhaps it didn't have one) and I wasn't aware of potential DPF issues before I bought the A3.

The car was last serviced in July 19. Just Oil and filter change. I've had the fault codes read and only one fault was returned and that was with the Gearbox Neutral Position Sensor (which is probably why my start/stop isn't working, but anyway that's a separate issue and one i'm not too bothered about!).
I guess the car isn't getting a chance to regenerate with the start stop short journeys that I do but when the light does illuminate I can force the regeneration by driving at 3000rpm for 10-20 mins so the car is able to regenerate.

Is this normal behaviour or is there something going on here?
What are the next steps in diagnosing any issue? A garage I went to recommended a Force Regen and then a Full service at a cost of £350 but there's no guarantee that would solve the problem. If it didn't, they recommended a DPF clean with fluids injected at a cost of £300.
I've been using Shell V Power diesel for the last full tank and a half.

Any advice would be great! Thanks,

Nathan

You need to find a garage that knows exactly how to deal with DPF/emissions faults and not just an everyday garage as they don’t tend to have much knowledge about that kind of stuff.
There’s a garage I follow on Facebook called JFS Tuning(but they’re in Yorkshire) who know how to deal with faulty dpf’s etc and do this most days from reading their posts.
They guy always says that the dpf light has come on because something else has caused it to( slow driving/ split pipe/ glow plug fault etc etc) so you need to find that fault first and then if needed you clean the DPF last (a proper clean is by removing it from the vehicle and can remove soot and ash).

it might be worth messaging them and ask if they know anyone in your area as from what I’ve seen they are or used to be part of a network that has garages all over the country.

 

[Daveyonthemove]

Many years ago I had a company in Banbury remove my DPF and remap the ECU to 'forget' the DPF cycles, this was on a Volvo.
I'm pretty sure at the point that the DPF was removed it was placed into an oven to burn off the excess soot before it could be gutted and refit.
Might be worth looking around for a company locally that can burn off the soot in an oven to give it a new lease of life?
I'm not saying it will cure your issue, but it's an option to consider.

 

[Nathan Grimes]

Thanks.
For now I have had an oil and filter change and had the glow plugs checked (they are working fine). So I'll see how it goes now that I know for a fact I have the right amount of oil in it and it's also the C3 low ash low saps stuff. It might make a difference but I'm not really expecting it to cure the problem to be honest. Expecting to see that DPF light again very soon!
Next step will probably be to look at getting the DPF cleaned but I'm still searching for a local DPF specialist!

Nathan

 

[Nathan Grimes]

I have just used the vag dpf app to take some readings of the dpf soot levels and I was very surprised to see the ash levels at 0.00.
Does that seem a bit odd? Wondering if a previous owner has set it to 0 in vcds.

 

[Daniel James]

I think my car is starting to go through this, yet again black edition at about 108k .. keep me posted with how you get on or what you get sorted, I've had A3's before with the same errors, again I don't do the mileage but recently gave my car a bit of hooning (on private roads) and for a while on boost i was getting like a white/blue smoke coming out ... then a couple of days after normal driving and short journeys my DPF light flashed up .. I'm guessing the smoke before hand was the car trying to re-gen but not completing .... I think if i can if i can find a company near to me that don't charge the earth I will have the DPF opened / gutted and then put back on then mapped out .. anyone know of anyone local to me (Stotfold, Hertfordshire) they do this?

 

[henkkeumus]

How much KM do you drive daily?

I've also had a 1.6 TDI, loved it but sold it because I only drove like 30KM a day. The DPF will get full of oxide **** and the light will come on. If you drive a good 70KM the DPF will re generate itself and it's good. Then a week or so later the light turns on again because I didnt drove enough KM's..

This went on and on.. Moral of the story, only drive a diesel when you drive like minimum of ~80KM's a day (to work and back) to get the motor on temp to regenerate. Otherwise your DPF will get full and won't regenerate itself in those short rides. Because of the short ride the motor and DPF can't get the right tempature to regenerate and burn the last oxide from the cat.

Mind my spelling, I'm Dutch so I'm sorry in advance

 

[Nathan Grimes]

I think my car is starting to go through this, yet again black edition at about 108k .. keep me posted with how you get on or what you get sorted, I've had A3's before with the same errors, again I don't do the mileage but recently gave my car a bit of hooning (on private roads) and for a while on boost i was getting like a white/blue smoke coming out ... then a couple of days after normal driving and short journeys my DPF light flashed up .. I'm guessing the smoke before hand was the car trying to re-gen but not completing .... I think if i can if i can find a company near to me that don't charge the earth I will have the DPF opened / gutted and then put back on then mapped out .. anyone know of anyone local to me (Stotfold, Hertfordshire) they do this?

How often is your DPF light coming on? I'm getting mine come on every couple of weeks which is no more than a 100 miles for me.
I've got it booked in with a Diesel specialist garage on Wednesday to test the DPF pressure and Exhaust temp sensors and also check everything else that is involved with DPF regeneration. He said if they don't find a fault it might be worth me getting it cleaned but the VAG DPF app is showing my ash level at 0.00 which seems odd and I'm not convinced that would solve the issue.
Will eagerly wait to see what they find (if anything) but I'm also seriously considering going down the gutting/remapping route. In some cases it seems to be cheaper to gut/remap the DPF than clean it!

 

[Retroman]

The DPF app will extract information from the car's central computer i.e. ECU. The fact that it shows 0% perhaps hints at a sensor giving erroneous information to the ECU rather than there actually being 0% carbon build up. If the ECU constantly thinks there is 0% carbon it won't trigger a regen and so carbon will build up until its physical presence causes a problem elsewhere.

 

[Nathan Grimes]

The DPF app will extract information from the car's central computer i.e. ECU. The fact that it shows 0% perhaps hints at a sensor giving erroneous information to the ECU rather than there actually being 0% carbon build up. If the ECU constantly thinks there is 0% carbon it won't trigger a regen and so carbon will build up until its physical presence causes a problem elsewhere.

The Soot mass currently shows 22.18 but the Oil Ash residue shows 0.00. The app shows 97% blockage. Surely it should regen based on the high Soot Mass reading? I'm not clear at what point the DPF light comes on but I'm expecting to see it again very shortly with that Soot reading!
I am hoping you are right and that a sensor is giving dodgy readings but there aren't any fault codes pointing to a sensor when I scan with Carista OBD adapter.

 

[Daveyonthemove]

If you are only doing 100 miles per fortnight, then you are not doing enough driving for the DPF to regenerate, hence why it's getting clogged so often.
You need to give the car a good run over quite a few miles to get the engine hot, keep it hot, and complete a regen.

A good drive up the motorway in 4th will get things going, if you are able to cover 20-30 miles constant.

 

[Daniel James]

How often is your DPF light coming on? I'm getting mine come on every couple of weeks which is no more than a 100 miles for me.
I've got it booked in with a Diesel specialist garage on Wednesday to test the DPF pressure and Exhaust temp sensors and also check everything else that is involved with DPF regeneration. He said if they don't find a fault it might be worth me getting it cleaned but the VAG DPF app is showing my ash level at 0.00 which seems odd and I'm not convinced that would solve the issue.
Will eagerly wait to see what they find (if anything) but I'm also seriously considering going down the gutting/remapping route. In some cases it seems to be cheaper to gut/remap the DPF than clean it!

Well mine has come on for the first time last week as I've only had the car for about 6 months ... but I know the previous owner used to do quite a lot of mileage for work so I can image the car has had a bit of a shock since I only do a 5min drive to work and 5min drive back ...

 

[henkkeumus]

Well mine has come on for the first time last week as I've only had the car for about 6 months ... but I know the previous owner used to do quite a lot of mileage for work so I can image the car has had a bit of a shock since I only do a 5min drive to work and 5min drive back ...

Mate thats waaaaaaaaaay to little miles for a diesel with DPF. If i were you I would consider getting the DPF out or buy a petrol.

Ive had to sell my A3 2012 1.6TDI for the same reason... In the Netherlands you cant remove a DPF filter if the car is above MJ2011/2022 so I had to go for a petrol even tho I drive enough KM's for a diesel yearly. I didnt made enough KMs a day/week to get the engine hot for it to regenerate itself.

I had to drive around in the weekends for a long time so the DOF would clean itself.

Verstuurd vanaf mijn ONEPLUS A5010 met Tapatalk

 

[Daniel James]

yea that's what im finding now, and only reason I went for diesel is because I couldn't find a petrol in the same spec in my price bracket

 

[henkkeumus]

yea that's what im finding now, and only reason I went for diesel is because I couldn't find a petrol in the same spec in my price bracket

Hard descision, it also was hard for mee since it was an S-Line A3 with a color you don't see much around.
The car would be less worth everyday I waited so just got a 1.4TFSI instead.

The TFSI engines don't have a great reputation, so I was always a bit shivery about them. But the 1.4 TFSI treats me well and doesn't use any extra oil .

 

[ab1702]

The Soot mass currently shows 22.18 but the Oil Ash residue shows 0.00. The app shows 97% blockage. Surely it should regen based on the high Soot Mass reading? I'm not clear at what point the DPF light comes on but I'm expecting to see it again very shortly with that Soot reading!
I am hoping you are right and that a sensor is giving dodgy readings but there aren't any fault codes pointing to a sensor when I scan with Carista OBD adapter.

Dont listen to these that are saying you don’t use it enough that’s why it’s blocked as thats got nothing to do with it, these are probably the guys that drive petrols.
It’s more down to how you drive it and not how far you drive it. If you look in the handbook it tells you that if the dpf light comes on then you have to drive for as long as possible above 2000 rpm until the light goes off. If you go by that theory most of the time when the dpf light isn’t on then you will stop it from coming on as the higher rpm burns the soot off. However if you’re constantly doing 30 or 40mph in 5th or 6th gear then the dpf is going to have more chance to block up so then it’s your fault.
Having said that if nothing is faulty then the car should regenerate at some point on its own if the engine is running for long enough, for instance maybe on your weekend runs.
I have a 2010 170 tdi and do 5000 miles a year at most and my dpf light has never come on.
It sounds to me like something is faulty though if vcds says it has 0 ash as that’s pretty much impossible if the light is coming on and your car has over 100000 miles.
You don’t want to get the dpf cleaned until the fault has been fixed or until it’s been proven that nothing is at fault and it’s because of your driving style otherwise it will just fill up again.
Having the glow plugs checked is a good starting point as cars don’t usually regenerate with faulty glow plugs but you would have had an emissions light on the dash anyway if a glow plug was faulty.
There are lots of other things too that can affect it such as dpf pressure sensors, split hoses/pipes, too much oil or wrong oil so you need a garage that can check all these things before you get the dpf cleaned, cleaning the dpf should be the last thing you do.