2008 audi a4 2.0tdi (b7) dpf regeneration??
2008 audi a4 2.0tdi (b7) dpf regeneration??
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Discussion

DomPritchard

Original Poster:

139 posts

180 months

Friday 10th February 2012
quotequote all
hi, just looking for some advice/guidanse
been reading on some forums now and it looks like my car would really benefit from dpf regeneration. Some say i can do this by driving at a constant speed with the car revs at 2000rpm for aprox 15min.would check the owners manual but its in german hehe.
would hope for someone to give me detailed steps on how to proceed in a dpf regeneration correctly.
thanks Dom.

Dr G

16,005 posts

273 months

Friday 10th February 2012
quotequote all
If it's still idling high and rough (you mentioned this in your other thread) then you need to drive for 20 minutes at high revs to let the filter heat up and burn the crap off. 2/3 around town and 3/4 motorway with a bit of right foot normally does it.

If this doesn't clear it you'll need to get it into a dealer quickly. If it's left clogged you can damage it very easily.

Tame Technician

2,467 posts

235 months

Friday 10th February 2012
quotequote all
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.


DomPritchard

Original Poster:

139 posts

180 months

Friday 10th February 2012
quotequote all
thanks a million for your comment tame technician. i get exactly what you say in the begining of your text with revs higher feels like throttle sticking etc. but have never seen light appear on the dash,tbh never looked out for it but will now, would my car/dpf filter benefit from me doing what you have explaind at the bottom, drive 3000-3500rpm 20 min etc?? even if i dont get the light on the dash?
seems to happen to me every 600km,and lasts aprox 10min.
Thanks Dom.

Tame Technician

2,467 posts

235 months

Friday 10th February 2012
quotequote all
If the revs are up and throttle eratic, it will definatly benefit from being driven as described.

It might not make any difference if the revs etc are back to normal, but it wont hurt either.

DomPritchard

Original Poster:

139 posts

180 months

Friday 10th February 2012
quotequote all
Great thanks, i will hopefully get the chance to take the car for a drive tonight. Will see it helps, hope so. I will get back to you with my situation, and if not sorted maybe you can recoment something else i can do.
Cheers, have a good weekend smile

DomPritchard

Original Poster:

139 posts

180 months

Friday 10th February 2012
quotequote all
hi, just getting back to you guys with some further information, (maybe the key to the problem)just taken the car out to do a manual dpf regeneration step by step after the help from members of forums.
came home and just did a random check on the oil, looks to me like its clearly over MAX. read on oil fill cap, warning overfill of oil can damage catalyc convertor, thiniking it mite also effect the dps, causing the car to keep trying to regenerate often.
thinking back when i first bought the car couldnt remember having the issue with the dps, but after aprox 2 months of owning the car i took it into my audi dealer for a service, they changed the oil, and thinking about it, the dps problem started not long after.maybe because it was filled with too much oil.
what do you guys think??
thanks Dom

pwd95

8,459 posts

269 months

Saturday 11th February 2012
quotequote all
DomPritchard said:
hi, just getting back to you guys with some further information, (maybe the key to the problem)just taken the car out to do a manual dpf regeneration step by step after the help from members of forums.
came home and just did a random check on the oil, looks to me like its clearly over MAX. read on oil fill cap, warning overfill of oil can damage catalyc convertor, thiniking it mite also effect the dps, causing the car to keep trying to regenerate often.
thinking back when i first bought the car couldnt remember having the issue with the dps, but after aprox 2 months of owning the car i took it into my audi dealer for a service, they changed the oil, and thinking about it, the dps problem started not long after.maybe because it was filled with too much oil.
what do you guys think??
thanks Dom
Please update us when you establish this fact. yes

DomPritchard

Original Poster:

139 posts

180 months

Wednesday 15th February 2012
quotequote all
Today took the car back to audi. They took out 0,31dl (300ml) so i hope this will help the dpf filter
,so it dosent have to regenarate so often. Need them to check the car to make sure the extra oil has not caused other damage. (fingers crossed)

Tame Technician

2,467 posts

235 months

Wednesday 15th February 2012
quotequote all
300ml is nothing, I wouldnt think its made the slightest difference.

If the DPF is regenerating more often than before, I dont thinks its going to be down to that slight overfill. My money will always be on a failed, or begining to fail, DPF pressure sensor.




DomPritchard

Original Poster:

139 posts

180 months

Thursday 16th February 2012
quotequote all
I will check into the sensor, is it possible to find out if there is a problem with the sensor just by taking it to audi and they can then plug it into the computer? I agree the 300ml of oil they took out is nothing but that must mean when they filled oil in the service 6 months ago they must have heavily overfilled, car has driven close to 10,000km sinse the last service. What do you think?
Thanx

bilotex

1 posts

144 months

Sunday 16th November 2014
quotequote all
DomPritchard said:
Today took the car back to audi. They took out 0,31dl (300ml) so i hope this will help the dpf filter
,so it dosent have to regenarate so often. Need them to check the car to make sure the extra oil has not caused other damage. (fingers crossed)
Same problem, after oil change DPF filter warning lamp on! immediately, drive few kilometers only.

liner33

10,861 posts

233 months

Monday 17th November 2014
quotequote all
How many miles on the car? could the dpf be getting full?