Audi Q7 - DPF will not regenerate on its own - Advice please
Discussion
Hi,
My first post on here - hoping for some much needed assistance please!
I have an Audi Q7 2008 - 3.0 diesel which has a persistant DPF regeneration issue. It appears that the car will not force regenerate on its own - every couple of months of driving it, we keep getting a lot of smoke from the back of the car and then eventually the DPF light appears on again. We have had it in two different garages (both of which i have friends/mechanics there).
Here's the history:
1st local independant Garage
- issue of DPF smoking as well as car going into limp mode (coil light flasing on dashboard) when you accelerate/go uphill. We had turbo taken away, stripped and fully re-conditioned, EGR value sent away and re-conditioned, DPF filter sent away and re-conditioned. Also the CAT had a fault where it had turned in to an incorrect position. This was sent away - they couldn't re-seat it, so removed it instead (saving a further £700 bill for replacement one).
Car was fine after that, no more limp mode, really solid power. A few weeks later car started smoking. Given back to garage, mechanic had DPF hard-coded/registered to computer, then forced regenerated. Car was fine for a few weeks, then same again. Mechanic advised us to give to Audi to put onto their own specialist diagnostic kit, as his computer only gave a limited number of readings.
2nd Garage (specialist Audi/VW garage with full Audi diagnostic computers - same kit as main Audi dealer).
- car put on diagnostic computers, fault showing DPF full, cleaned through with special fluid, and then road-tested over couple of days with computers plugged in checking levels. Car appeared to be fine, levels good. We drove it again, and car lasted 4/6 weeks, then some smoke from back at times, which got worse and worse over next 2 weeks. Eventually horrific smoking and DPF light coming back on. Nasty smell too. Back to garage (where it is now) - no errors on computer at all, DPF / EGR all showing ok, however been told that the car will seemingly not regenerate on its own. Another force re-gen done by garage - they've since taken it out for last few days and monitored all levels after trips, all looks ok (exactly same as last time).
We usually drive the car predominately on long trips (Brighton to London and back), which should give car plenty enough time to regen on its own.
Our problem is that no actual error can be diagnosed from garage, their computers show no faults on car. We can't keep force re-generating the car each time it plays up. One loose theory the garage has is that the lack of CAT is not getting the DPF hot enough to regen, although they have been told by other specialists that not having a CAT present shouldn't make any difference to this. It's also a very expensive theory to eliminate at this stage (£500-£700), especially if it makes no difference!
Sorry for the long post, but thought it best to give a full run-down of work done.
Can anyone please offer any advice as to what else might be causing this? We're coming to the end of our tether!
Thanks in advance
Billy
My first post on here - hoping for some much needed assistance please!
I have an Audi Q7 2008 - 3.0 diesel which has a persistant DPF regeneration issue. It appears that the car will not force regenerate on its own - every couple of months of driving it, we keep getting a lot of smoke from the back of the car and then eventually the DPF light appears on again. We have had it in two different garages (both of which i have friends/mechanics there).
Here's the history:
1st local independant Garage
- issue of DPF smoking as well as car going into limp mode (coil light flasing on dashboard) when you accelerate/go uphill. We had turbo taken away, stripped and fully re-conditioned, EGR value sent away and re-conditioned, DPF filter sent away and re-conditioned. Also the CAT had a fault where it had turned in to an incorrect position. This was sent away - they couldn't re-seat it, so removed it instead (saving a further £700 bill for replacement one).
Car was fine after that, no more limp mode, really solid power. A few weeks later car started smoking. Given back to garage, mechanic had DPF hard-coded/registered to computer, then forced regenerated. Car was fine for a few weeks, then same again. Mechanic advised us to give to Audi to put onto their own specialist diagnostic kit, as his computer only gave a limited number of readings.
2nd Garage (specialist Audi/VW garage with full Audi diagnostic computers - same kit as main Audi dealer).
- car put on diagnostic computers, fault showing DPF full, cleaned through with special fluid, and then road-tested over couple of days with computers plugged in checking levels. Car appeared to be fine, levels good. We drove it again, and car lasted 4/6 weeks, then some smoke from back at times, which got worse and worse over next 2 weeks. Eventually horrific smoking and DPF light coming back on. Nasty smell too. Back to garage (where it is now) - no errors on computer at all, DPF / EGR all showing ok, however been told that the car will seemingly not regenerate on its own. Another force re-gen done by garage - they've since taken it out for last few days and monitored all levels after trips, all looks ok (exactly same as last time).
We usually drive the car predominately on long trips (Brighton to London and back), which should give car plenty enough time to regen on its own.
Our problem is that no actual error can be diagnosed from garage, their computers show no faults on car. We can't keep force re-generating the car each time it plays up. One loose theory the garage has is that the lack of CAT is not getting the DPF hot enough to regen, although they have been told by other specialists that not having a CAT present shouldn't make any difference to this. It's also a very expensive theory to eliminate at this stage (£500-£700), especially if it makes no difference!
Sorry for the long post, but thought it best to give a full run-down of work done.
Can anyone please offer any advice as to what else might be causing this? We're coming to the end of our tether!
Thanks in advance
Billy
Pistonheader101 said:
Dpf delete and remap. Problem solved.
Pollute away since they are taxing you for it anyway.
Hi, thanks for the quick reply.Pollute away since they are taxing you for it anyway.
Yes, I have really given this option some thought. Can I ask how does it stand with getting the car through future MOT's though?
- I know they have to do a DPF test as part of the MOT, what happens then?
- Are the emission levels much higher without it?
- Will this actually stop the smoking completely?
- Do you know how much this remap should cost?
Thanks very much
Billy
Edited by billyemsley on Friday 18th August 16:25
Edited by billyemsley on Friday 18th August 16:25
Smoking in a diesel is usually from over fueling so could be injectors are worn (can check with vcds) or a minor leak on the inlet side giving too much air so car trying to compensate by over fueling.
Did they replace the DPF or have they just cleaned it as it could simply be it is knackered.
I had the Dpf warning on my Q7 ages ago but that was when I was not very well so did a few short trips and ran it low on fuel so it would not auto regen.
Are there no other fault codes as on some vehicles things like it being low on aircon gas etc can stop the regen process.
Did they replace the DPF or have they just cleaned it as it could simply be it is knackered.
I had the Dpf warning on my Q7 ages ago but that was when I was not very well so did a few short trips and ran it low on fuel so it would not auto regen.
Are there no other fault codes as on some vehicles things like it being low on aircon gas etc can stop the regen process.
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