DPF (particle filter)

It may be needing to do a Re-gen.

As far as im aware if the light comes on "RED" it means the DPF is blocked and requires cleaning and then the fault re-setting.
 
I took it to where I got it two weeks ago hen the light was on again an paid £60 for them to reprogramme it or something. They told me to do more motorway driving so the filter doesn't get clogged up. Did 400 motorway last weekend and the light came on today :s
 
Unsure then, I always check my own faults before i send it to Audi, i mean all you can do is ring Audi - let them know that the fault has not been resolved and you have driven as instructed.

See what they have to say to that, but i wouldnt be prepaired to pay any more ££
 
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Give them a bell tomorrow, and keep us posted on what they say :icon_thumright:
 
I have exactly the same problem mate, because I only do short journeys during the week I have to take it out for a blast everyweek to re-gen it. Also considered having it deleted however, to many £££ at the moment.
 
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As far as i am aware, it will pass the Emissions/smoke test - but i am unsure as to if it has to pass a Visual inspection.

Bearing in mind there is a under pan on the car so that would need to be removed to have a look.

Knowing the lads @ the garage would always be a good start aswell :happy:
 
I shouldn't be having this prob coz I clocked 400 miles this weekend lol. Yeah sounds a good idea getting it deleted or removed but £££. I read a thread where after deleting it the cars been re mapped to about 200-205bhp which would be exciting
 
I noticed that I was having problems with my DPF filter light always coming on even although I was doing lots of motorway driving.

I use to run the car on tesco cheap diesel but now I've changed to shell v power and now the car feels so more responsive and less sluggish. I very rarly get the DPF light on now every now and agen when driving in town.

I think the cheap desiel was clogging the car and filter up. now I've only run the car on shell vpower has cleaners in it too.

You might just have a faulty sensor or the fact you drive in the town most the time could be the cause.

The DPF is a pain in the **** but this seemed to fix it for me. If you do fill the car with cheap desiel it might be worth trying v power.

Definitely let the garage know ur still having problems seeing as you paid 60 quid to have the fault fixed and its still there.
 
To re-gen the dpf you need to drive the car for 20mintues at about 2500rpm to get enough heat into the filter to burn off the soot.
Try driving in 5th on the m'way for a while. There will probably be a fair bit of black soot coming from the exhaust when it re-gens itself(nothing to worry about).

The soot does get burn't off but still leaves a small amount of ash in the filter, eventually you will have to replace the dpf, i think Audi suggest this at around 120,000 miles.

If the light is coming on more often i think your filter will be on its way out. Time for a dpf delete and remap :D
Probably cheaper than a new dpf anyway!
 
Right I never know what the right advice is to help the car regen

The book says drive in 3/4 gear about 40mph to clear it but if your on a motorway you Carnt do that

So do you have to drive around 40 to make the car go into regen mode ???

Or is it just a case of sitting in 4th and letting the revs get higher meaning more heat going to DPF ??


I don't suffer like I use to with the DPF but every now and again it comes up and I have to regen just be good to know what others do.
 
To re-gen the dpf you need to drive the car for 20mintues at about 2500rpm to get enough heat into the filter to burn off the soot.
Try driving in 5th on the m'way for a while. There will probably be a fair bit of black soot coming from the exhaust when it re-gens itself(nothing to worry about).

I'm not convinced that motorway driving is the best way to prevent a blocked DPF.

I live in an area with some fairly steep hills on 60mph roads. I drive these roads regularly as well as doing lots of motorway miles.

So how come I can do a week of loads of motorway driving but the time the car decides to regen is accelerating up the hill out of town when the engine has been on for only 5 minutes? Temp gauge isn't even quite on 90. It does it every 2 weeks on average at exactly the same spot. You feel the engine cough as you go up the hill and then it coughs again about 2 miles down the road. When I get home (another mile or so) the exhaust will be red hot.

Seems to me the ECU is looking at heat and load and when it senses the ideal conditions it decides to go into regen.
 
The engine will be running cleaner on the motorway so less regens needed and it will be so slight you won't detect it. But driving round town or even a-roads with varying throttle loads the regen will be needed sooner so you will notice it more.

If the DPF light comes on the best way to clear it is steady state cruising at about 60ish on the motorway, I generally use 6th gear if up to temp keeping the revs around or below 2000rpm; the worst scenario is the DPF trying to regenerate whilst you are town driving filling it up at the same time!


I had the DPF removed off my old 170 and I kept the DPF downpipe (it was replace with a Miltek downpipe). I gutted the DPF and it was a clean as a whistle inside, not really any soot inside it at all. It's like interconnecting honeycombs of tiny holes. That was on an 06 car that had done around 90,000miles. I had no problems with the car with the DPF on but just wanted to remove it for better mpg and future proof IT.
 
Are you driving at 2500rpm on the m'way? If your cruising in 6th there may not be enough load on the engine?
Just theories by the way, i'm a new audi owner so this is just from what i've read online.

Im sure it said it shouldn't do the re-gen when the engine is cold either :S but i think you are right the ecu checks engine load and temp before starting the re-gen.

Does the DPF warning light come on before it does a re-gen? I've only had my car a week but was thinking about giving it a good motorway blast to clear it, or do i have to wait for the light to come on?
 
When I take mine for a blast I drive in 4th at around 60-70. Does the trick after about 10mins or so ;)
 
Are you driving at 2500rpm on the m'way? If your cruising in 6th there may not be enough load on the engine?
Just theories by the way, i'm a new audi owner so this is just from what i've read online.

Im sure it said it shouldn't do the re-gen when the engine is cold either :S but i think you are right the ecu checks engine load and temp before starting the re-gen.

Does the DPF warning light come on before it does a re-gen? I've only had my car a week but was thinking about giving it a good motorway blast to clear it, or do i have to wait for the light to come on?

No light. You may feel it cough if you are accelerating at the time.

If it wasn't for the blistering heat off of the exhaust and the smell, I would never know its in regen. Seems to be totally seamless.

I was surprised it decided to regen so quickly from cold but I guess just because the engine itself isn't quite up to operating temp it doesn't mean the exhaust isn't. The ECU detects the conditions and goes for it.
 
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A good motorway blast isn't really the right way to do it,;the engine needs to be up to temp but at lower revs with steady throttle (the latter being perhaps the important bit) so steady motorway cruising is best scenario. A really low speed figure is quoted in the handbook I think.

The regen has it's own mode to clear the dpf; the best you can do is use the lightest throttle inputs and let it do it's thing, giving it a thrash will just put more soot in the dpf and is counteractive to the DPF regeneration cycle which the driver doesn't control but can help to a degree with steadier driving.

There are a few varying degrees of regeneration;

1. happens as the normal regen cycle under normal driving; no lights on dash, the throttle pedal may beomce a bit inconsistent and the idle raised a touch.

2. DPF light comes on the centre computer, regen is needed to clear it and is best to drive steady on motorway, usuallyclears in a couple of miles on my car

3. DPF light plus glow plug light(?) car could go in to limp mode with reduced power if the 2nd regen state is not done

On my car, since the AUDI injector recall program the car definitely regenerates as in point 1 more times, I think this is to reduce the risk of it getting to a point of no return where it goes in limp. The car has been in point 2 stage maybe 2 times in over 18months and it's usually after a succession of cold start short journeys (to local shops etc).
 
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Just found this post on pistonheads about the dpf regen, worth a read.
Those that keep having the regen occuring at odd times may need a new sensor?



Generally the way it works is the cars DPF pressure sensor tells the ECU how blocked the DPF is when it get slightly clogged it does a sort of lower level (passive) self regen and holds the revs up a bit and has generally slightly poor throttle responce, almost feels like the throttle sticks sometime.

If sensor and ECU deem its proper blocked, it will put the DPF warning light on the dash, then the car is requesting you drive it in the DPF regen style, (see bottom). This is full on active regen the throttle will be crap and engine may smell very hot while you do this (dont panic this is normal) If you condinue to drive without regening with the DPF light on, eventualy the check engine light will come on and you will have to take it to the dealer. The pressure sensors are a bit rubbish and fail from time to time and confuse the F**k out of the ECU making it regen to often or not noticing that you have done the regen correctly when requested by the car and still putting the check light on as if you havnt done anything about it.

In the event of a sudden change in the car, seemingly regening all the time, when it didnt before, could point to sensor failure. If its periodical every 500-1000 miles, then its the normal lower level regen happening.


How to regen. This will be most effective when the car is in regen mode, either you have noticed it doing it passivly or the DPF light is on.

Regen driving style, light to medium load higher rpm is the key, dont just thrash it to the red line thats almost as bad as pottering about. Go across the gate with the gear selector put it in a gear where the engine is doing 3000-3500 rpm and just maintain speed. If your doing 70 on a main road thats great, just do it in 4th instead of 6th. If your doing 50 on an A road do it in 3rd. 20 mins like this, with one or two slow downs and speed ups with full throttle helps clear out the EGR at the same time.
 
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I have a lot of thinking to do

Unless you are seeing the light all the time, don't panic.

I believe if you've had the injectors done Audi will have also performed an update that means the DPF does low level regens more often.

Unless it starts giving problems I'll leave well alone!
 
Get it scanned with Vagcom. There's a sensor on it that can go which can cause issues (just had mine done as it was picked up while looking at another issue).

You can also force a regen in Vagcom but others will know more than me.
 
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In 12k miles, I've had to regen maybe five or six times. I've noticed that the gear change indicator seems to suggest staying in a lower gear longer, the regen will happen when doing my ten minute commute home which is around town.
 
Ah no worries mate, I had the same car and had to return it with similar problems.

If I was you and its ok besides this, the DPF delete and re-map seems the best option, as long as the MOT side of things is ok.

Does it feel hesitant at all? You can tell when its trying to do its passive regen as the revs on idle go from about 800 to 1000 and this can be heard. When mine did this it had other issues and was often undrivable, if yours is ok its probably just due to the driving style, mine came on again after 70 miles on the motorway and 1 hour 40 minutes driving at the final straw point!
 
I've just been on motorway for 30 mins purposely keeping revs at 3000rpm or above and it's still on ://

That isn't what the handbook advises or what I would suggest you do, the light on mine goes out everytime after no more than 5miles at 60mph in 6th when up to temp or somewhere around 2000rpm. The exhaust temp is raised through software, I honestly think running the engine on lightest load at low revs is the way to go.
 
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They do all seem to vary so worth doing a slower journey/higher gear and see what happens! My thinking is that higher revs means you're putting more soot in the box the car is trying to clear!
 

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