A6 DPF Query

[Wesley949]

Hi all, hope that everyone is ok and keeping well.

Just a query regarding the dreaded DPF.  I have noticed that my vehicle (2016 A6 2.0 TDI Ultra 190PS) seems to be carrying out the automatic regeneration a lot lately.  I had previous, a 2014 A4 2.0 TDI and I do not remember that being as bad with the regeneration cycle, or maybe I am more cautious and notice the tell-tale signs of late.  My driving style has never changed and I drive the A6 the same as I ever did on the A4 but seems that every other journey, my REVS sit at 1000RPM's, vibrations felt through the car, Radiator Cooling fans on and the horrid burning smell (like overheated brakes).  Not once has any DPF warning light illuminated, in either car but this A6 seems to do this every other day.

I do drive to work which is 6-miles and in this cold weather lately, the car Temperature sits at normal just as I park-up so I cannot drive at the 2000RPM's for 20-minutes as per most websites and the handbook.  Even when I came off the motorway a few weeks ago, driving for 2-hours and the regeneration cycle started as the REVs sat on 1000RPM's plus but surely I had burnt off the particles during the motorway driving?

I know after so many failed attempts, the DPF light will possibly come on, but when the car is doing the regeneration, Ive let my car idle for almost 20-minutes (twice in total)  and the REVs did not drop below 1000RPM's but I had to turn the car off as I had things to do.

Am I doing anything wrong or should I just take a step back at tad.

[rbdazza]

I doubt it will finish a regen susccesfully while stationary. You need 4th or 5th gear up a decent hillly a road or motorway really 

 

I personally hate hate the things and got rid of mine soon after buying my car. Have you checked your engine oil level? I'd be wary if it is doing so many regens on short journeys or when stationary. 

[Trevor]

There are several versions of the DPF regeneration process but it is best to follow the genuine manufacturers instructions.

Some manufacturers insist that the fuel tank is full and that the revs are constantly maintained over say 3000 rpm for in excess of 10 minutes (so that means un-interupted motorway driving, etc

If not, then a forced regen would be you only other option.

Keep us updated on your progress

Cheers  Trevor

[rbdazza]

These things are the spawn of the devil I swear!

[Wesley949]

On 29/01/2017 at 7:46 PM, rbdazza said:

I doubt it will finish a regen susccesfully while stationary. You need 4th or 5th gear up a decent hillly a road or motorway really 

 

I personally hate hate the things and got rid of mine soon after buying my car. Have you checked your engine oil level? I'd be wary if it is doing so many regens on short journeys or when stationary. 

I think I must have misread the Operating manual as I'm sure it can happen whilst stationary but I have used the manual override and kept the REVs at 2000 when driving at 50mph for about twenty minutes, or as much as I can on some journeys but once once the engine has warmed up, just difficult to do early in the morning driving to work.

Yeah, I heard that failed DPF regeneration can cause unburnt diesel to fall in to the oil sump.  Not a good idea at all.  I do believe that modern diesels vehicle have a sensor to warn about oil contamination but I've never put this to the test and will probably get the oil changed before the service mileage stated on the MMI screen, not yet though as the car was only registered late-November 2016.

[Wesley949]

6 hours ago, Trevor said:

There are several versions of the DPF regeneration process but it is best to follow the genuine manufacturers instructions.

Some manufacturers insist that the fuel tank is full and that the revs are constantly maintained over say 3000 rpm for in excess of 10 minutes (so that means un-interupted motorway driving, etc

If not, then a forced regen would be you only other option.

Keep us updated on your progress

Cheers  Trevor

This is the first diesel Ive had that uses Adblue system and the whole vehicle is better than my previous Audi (A4 Saloon) but this vehicle seems more sensitive so maybe its the Ultra engine doing what it needs to and maybe I am mis-reading the signs?  I do try and burn off the particles using the manual override on the AUTO system keeping the REVs around or over the 2000RPM's of which must do something as the car feels a lot smoother to drive afterwards.  The downside to this, the diesel seems to burn quicker and affects my Miles to Empty figure.  I can't keep doing this every time, can I?

But when on the Motorway, set in AUTO or ECO, at 70mph, the REVs do not even touch anywhere near the 2000RPM marker so can I assume that even low REVs on the Motorway, this is still adequate enough to burn everything off?

[Wesley949]

56 minutes ago, rbdazza said:

These things are the spawn of the devil I swear!

Quite possibly.  Heard too many bad reports about them, even from the Breakdown recovery companies.

Never had any DPF issues on my previous Audi A4 but maybe this new A6 Ultra is just sensitive.

I've no plans at all to remove the DPF, too much hassle, affects Warranty and needs to be reinstalled upon every service/ MOT etc..

[rbdazza]

My experience with ad blue systems is limited. It helps get to temp without dumping extra diesel into the engine. So, oil contamination might not be such a problem for you. 

If your manual states you can do it stationary then carry on. You don't have a problem really until the light comes on but don't forget the dpf system inherently causes lower mpg in favour of lower emissions. 

A bit like the EGR valves, reduces NOx but creates more soot, dpf introduced to reduce soot. Both cause lower mpg. The mind boggles. 

When you get t serviced they can plug the computer in and let you know how full the dpf is and the status of the recent regenerations and whether or not it has been succesful. 

[Beezil]

I believe the DPF needs the temperature of high-revs to burn the soot off, which is why manufacturers recommend a blat down a fast road in a low gear.

Recently had a friend asking advice from me (I used to be a technician) as his Vx Insignia DPF light wouldn't go off. Garage had told him he needed a new DPF filter at a cost of £1500, but they suggested he may want to get it removed instead but would need to find someone willing to do this. When I checked this out I found that, yes, he could have been fined (£1-2k if memory serves) if they ever found out he had no DPF - would never have been found as a "dummy" DPF would have been fitted to replace the real thing but personally I wouldn't want to take the risk. Anyway, I suggested before doing anything else he try chucking a bottle of Forte DPF Cleaner through for £15, and low and behold, the light went off and stayed off!

So, my suggestion would be try the Forte Cleaner first.

[rbdazza]

bugger that, just get rid of it.

[Paul Duff]

I had loads of issues with the DPF on my car, had it in a few places crazy numbers being thrown around the car was in and out of limp mode.

ended up buying a cheep code reader - bought an exhaust pressure sensor and fixed it myself for £30 i was up and down the motorway trying to get it to re-gen even had a few forced re-gens and it wasn't even the DPF just a crazy little plastic sensor.

hope you get it sorted.

[niedzial1983]

Best option woukd be dpf delete :) 

[Dan3222]

Hhhmmm, I am going to be the sensible old f8rt here and say don't delete the DPF as your car is so new. Don't change or alter anything like that until at least 3 yrs old. You will be up a rather dark brown creek without a paddle if something goes wrong under warranty!!

With regards your issues, to burn off the DPF deposits you need to select a lower gear so you can keep the revs up higher, this significantly increases the exhaust gasses temp to actually burn the soot off. I would also use an injector cleaner every two to three fills of fuel. You state that a large  proportion of your driving is on low revs. This promotes gumming up of the injectors and therefore poor fuel atomisation, giving higher carbon deposits creating even more issues. Get some injector cleaner (I have used Millers for 3 years now in both van and A6) and blast the engine a bit, have a bit of fun, and clear the exhaust system out!!

[Beezil]

Just to clarify, you are technically breaking the law by removing your DPF. I mentioned previously (see above) about a friend of mine looking to remove his DPF. The garage suggested he may want to look at finding someone to do the removal for him as they were not willing to carry out the work as they would be heavily fined if the authorities tracked any DPF removal back to them. The car owner would be fined as well. There is an argument that most modern cars can still meet current emissions regulations without the DPF so therefore pass the MoT, but if you've removed the DPF and it does fail you're looking at the cost of refitting and the purchase of a new DPF unit assuming you haven't kept hold of it.

 

And remember if you've removed the DPF and the car is still in warranty period, Audi will more than likely argue that you've invalidated the warranty on anything to do with the engine, possibly even more.

 

It looks like I have the same model as you Wesley, and would suggest if its bothering you to put it into manual as soon as you get to m'way speed and knock down a couple of gears to get the revs over 3000rpm. I do occasionally get home after a 14-mile (mostly at 70mph) drive from work to have the fan running for 10/15 minutes once I've switched the ignition off, and believe this is to help dissipate the heat created by the DPF regen.

[Wesley949]

Sorry for the delays in responding.  Thank-you for your message.  Nice to know we share the same model and in all honestly, I am seeing many 2016 Audi A6's everywhere so there must have been a sale on somewhere, or they took advantage of the Audi Dealer contribution last-year, it helped me.  Keep seeing a few Black edition models...if only I could have afforded that at the time.

I still notice when using AUTO Drive Select, the Regeneration process seems to happen a lot and had even happened after coming off a Motorway (3-hr trip at 70mph).  But I have lately, been using the Manual system which is brilliant as I cannot stall it, LOL.  I try and use the Manual system twice a week as I only do short journeys mostly, but every 3-weeks drive from Essex to the West Midlands etc..  I do not hammer the car and I do not speed anymore but I did red-line the car once by accident as I forgot I was in manual but despite this being my third Diesel car, I still no nothing about the engine or its capabilities.

With the DPF, I know how to use the manual system and keep it about 2500 RPM pending on the road speed limit and it does clear very quickly.  But I purchased this car to save money and driving like Miss Daisy does save me money and I can usually get 750 Miles on a full tank, but driving like this causes DPF issues and you then need to drive at higher REVs to burn off the particulates, burn more fuel and do not get the full advantage of the fuel range on a single tank.  So, am I saving money?

I do like the fuel range from my vehicle and my previous A4 but I do miss Petrol engines.

[Beezil]

Just a little update to the thoughts of removing your DPF filter......

 

http://www.bbc.co.uk/news/uk-41761864

[Wesley949]

That was a useful link regarding the DPF....

Removing the DPF for me was never an option as it is too much hassle, especially having it refitted prior to having an M.O.T. so it is easier to learn to live with it and learn how to drive with it and never ignore the warnings, should they ever appear on the Dash and avoid short journeys.

[Bassam asif]

I have an Audi A6 ultra 16 plate. Not sure if any one can guide me.

problem:

car has stopped regenerating, only can do force regen via diagnostic

start/stop not working

car goes in limp mode when driving a slight uphill (randomly) sometimes it does it and sometimes it doesn’t.

I have had car fully serviced 

gearbox service (oil change)

no faults showing on diagnostic

no engine management light or any other warning light.

I’m stuck with this confusing problem.

egr valve is working ok

boost pressure showing correct reading

not sure wether this has anything to do with dpf? 

[Cillian]

Just to reply to Bassam Asif. My car is in with the exact same issues. The DPF is clogged because it hasn't done a regen in 19,000 miles..(I only have the bar 4 months.) They have no clue what caused it.

Audi want me to buy a new DPF..but I want to fix the problem causing the issue regens to stop. Then clean out the DPF and see how I get on. If anyone has any thoughts?