Dpf Advice Needed

[psings]

Hi guys,

A couple of years back my DPF would require an active regen around twice a week. It was taken to Audi who said there was nothing wrong and charged me around £200 for checking it over.

For over a year it's been running perfectly - I've done loads of short journeys and even managed to spend 4 hours driving in and out of central London stop-start traffic jams without the DPF actively regenerating once which I was surprised at given the history!

A few months ago I noticed that the car wasn't achieving decent MPG any more, and that it appeared to be regenerating every other day. This has since become much worse - some examples:

1. After a completed active regen on a Saturday I drove a 5 mile round trip to the shops on Sunday. Monday morning it started actively regenerating again.
   
   
2. I drove 42 miles to Portsmouth this Saturday, all free-flowing A-roads and motorway. DPF started an active regen at 35 miles into journey, completed after a 20 mile detour. Drove 6.5 miles in light traffic in Portsmouth then drove home.
   
   After 30 miles the car started an active regen again. Had to drive 25 miles at 50/60mph with a decent RPM before it cleared.
   
   Sunday (today) it was driven 18.5 miles on fast A-roads, then after driving 10 miles home it started active regen again. I had to drive it for 45 miles during which the DPF light came on, before it finally cleared - the 80 mile drive used over 1/4 tank of diesel!

I have recently taken it to Poole Audi who advised a dealer regen against my knowing that it wouldn't do much apart from make my pocket lighter.

They told me there was nothing wrong with the car and didn't appear to have looked into my concerns of strong diesel fume smells during regens and the fact that my consumption for journeys where I usually get 46MPG were now giving 39MPG.

I've had the car a fairly long time now and know its DPF quirks so I know when something is wrong.

I am now writing to Poole Audi to try and get them to properly look into the cause and find a resolution as I am appalled at their inability to resolve my problem.

Does anybody know any reason why the car is doing this?

VAG-COM shows no errors and also tells me that the DPF carbon mass is at 14.25. Again, another indicator that something is wrong as the ash-load was only at 9.01 this time last year, and 12.23 two months ago.

I have seen suggestions on the internet that the car may be overfuelling, may have injector seal leaks, a worn turbo or incorrectly adjusted timing belt... Does anyone have any other ideas?

Cheers,
Paul

 

[Geraldy212]

Psings, I believe that if you do a VCDS scan, you will be able to look at the measuring blocks to determine if the DPF is clogged with ash. If so, it may not be able to be cleared with the normal regeneration. Hope this is not the case. Worth a look I would say. Good luck.

 

[psings]

Hi Geraldy212,

That's correct - I've been checking for the past few weeks again and doing journeys logging the measuring block data so that I can provide them to Audi, along with route maps detailing how it's had to be driven recently to satisfy it.

The permanent ash load is currently reading as 14.25g so nowhere near the end-of-life 68g, but the load seems to be increasing very quickly as only two months ago it was 12.23g, so it's loaded 2.02g over only 1500 miles - this time last year it read 9.01g and since last year I've easily covered 15000 miles.

Something very strange going on, especially when it regens after less than 30 miles since the last regen on A-roads, then takes 45 miles and 1/4 tank of fuel to complete again.

The DIS gives an average 45.9MPG over those 80 miles, but by my calculations it works out at around 27MPG.