Constant DPF Regen after Miss Fueling - Help!

[johnstables]

Hi Everyone,

Hope you can help me out, had a miss fuel mishap about 2 months back, full tank of Petrol...into my Diesel Audi A3 ... 😞 ran for about 5 miles before shuddering to a stop. Got tank drained and got the Fuel filter replaced soon after but since then regens are occurring pretty much constantly till the point that the DPF light comes on and then in time goes into limp mode due to regen not completing. 

I got a forced regen done which helped for a few day, I got a https://www.terraclean.co.uk/science-behind-terraclean/ Terraclean done which cleaned the DPF, Injectors etc but still and issue. Local garage picked up a fault with the DPF sensor and this was replaced but still the same issue where it's constantly in regen, i note a lot of smoke out of the exhaust during this and i'm taking this to be unburnt fuel? always a smell at the exhaust end as well.

I think the DPF light is maybe just a symptom of another issue,my thoughts are that temps are not getting high enough to complete the regen? I'm not sure what next to look into, I mentioned the EGR valve to my local garage and that is quite a job to replace due to it's location on the car, maybe not the issue though, could it be the needing replacing after the missfuel? or maybe issues with the Injectors/Valves?

Any thoughts welcome!

Thanks

John

 

[cliffcoggin]

John.

You need to be aware that diesel fuel is the lubricant for the fuel pump and its absence can cause wear within the pump, because petrol has no lubricating properties. Furthermore petrol may have degraded seals at any point in the fuel system from the pump to the injectors. I am not saying these are definitely the causes of your problems, but they are distinct and very expensive possibilities.

[johnstables]

Thanks Cliff,

I'm back into limp mode with the flashing glow plug and engine lights on, basically failed DPF regen again.. I've a friend that has VCDS so will see what that shows up, if anything, As you say may be a myriad of things, all expensive 😞

John

[cliffcoggin]

Do let us know the outcome.

[johnstables]

Hi,

Fault scan was done Friday with the results shown below, the instruments faults I believe are related to a flat battery I had. 345 miles since last regen, counter for regen time 3.5hrs not sure if that's last successful timing or 3.5hrs before giving up?  The soot measured/calculated values are higher now 16/28g so I'll run a forced regen asap.  Also ran a few EGR tests that ran successfully and generated a lot of data that I can't read as such ha! but no faults shown. I've purchased VCDS myself so I can do more testing myself, any thoughts on the below welcome! maybe suggestions on what to measure once I get VCDS, thanks John 

Friday,15,November,2019,14:44:28:63929
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 7 x64
VCDS Version: 19.6.2.0 (x64)
Data version: 20190930 DS308.0
www.Ross-Tech.com

VIN: WAUZZZ8P7CA160343   License Plate: 
Mileage: 101230km-62901mi   Repair Order: 

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

Chassis Type: 8P-AU35 (7N0)
Scan: 01 03 08 09 10 15 16 17 19 22 25 42 44 46 52 55 56 61 77

VIN: WAUZZZ8P7CA160343   Mileage: 101230km-62901miles

01-Engine -- Status: Malfunction 0010
03-ABS Brakes -- Status: OK 0000
04-Steering Angle -- Status: OK 0000
08-Auto HVAC -- Status: OK 0000
09-Cent. Elect. -- Status: OK 0000
10-Park/Steer Assist -- Status: OK 0000
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: Malfunction 0010
19-CAN Gateway -- Status: OK 0000
22-AWD -- Status: OK 0000
25-Immobilizer -- Status: OK 0000
42-Door Elect, Driver -- Status: OK 0000
44-Steering Assist -- Status: OK 0000
46-Central Conv. -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
55-Headlight Range -- Status: OK 0000
56-Radio -- Status: OK 0000
61-Battery Regul. -- Status: OK 0000
77-Telephone -- Status: OK 0000
 
-------------------------------------------------------------------------------
Address 01: Engine (J623-CFGB)       Labels:. 03L-906-018-CFF.clb
   Part No SW: 03L 906 018 AL    HW: 03L 906 018 AG
   Component: R4 2,0L EDC   H27 7764  
   Revision: 41H27---    Serial number: AUX7Z0L3FNJ0F9
   Coding: 00190032042701080000
   Shop #: WSC 06314 000 00000
   ASAM Dataset: EV_ECM20TDI01103L906018AL 003003
   ROD: EV_ECM20TDI01103L906018AL.rod
   VCID: 74ECD1A0DF4296EFB3-8020

1 Fault Found:
8194 - Diesel Particulate Filter 
          P2458 00 [175] - Regeneration Duration
          MIL ON - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 101106 km
                    Date: 2019.11.11
                    Time: 08:42:54

                    Engine speed: 2093.00 /min
                    Normed load value: 0.0 %
                    Vehicle speed: 68 km/h
                    Coolant temperature: 73 °C
                    Intake air temperature: 7 °C
                    Ambient air pressure: 970 mbar
                    Voltage terminal 30: 14.680 V
                    Unlearning counter according OBD: 40
                    Counter for regeneration time of diesel particle filter: 12600.10 s
                    Particle filter: kilometers since last regeneration: 556045 m
                    Particle filter: soot mass measured: 11.47 g
                    Particle filter: soot mass calculated: 11.71 g
                    Particle filter: differential pressure: dynamic offset: -4 hPa

Readiness: 1 1 0 0 0 

Address 17: Instruments        Labels: 8P0-920-xxx-17-MY8.clb
   Part No SW: 8P0 920 983     HW: 8P0 920 983 
   Component: KOMBIINSTR. VDO H04 0150  
   Revision: D0H04003    Serial number: 2243L003021801
   Coding: 0261428
   Shop #: WSC 12345 067 57207
   VCID: 77F6E6AC0634FDF796-8022

2 Faults Found:
00446 - Function Limitation due to Under-Voltage 
            002 - Lower Limit Exceeded - Intermittent
             Freeze Frame:
                    Fault Status: 00100010
                    Fault Priority: 4
                    Fault Frequency: 2
                    Reset counter: 40
                    Mileage: 98780 km
                    Time Indication: 0
                    Date: 2019.09.02
                    Time: 00:00:19

00532 - Supply Voltage B+ 
            002 - Lower Limit Exceeded - Intermittent
             Freeze Frame:
                    Fault Status: 00100010
                    Fault Priority: 4
                    Fault Frequency: 2
                    Reset counter: 40
                    Mileage: 98780 km
                    Time Indication: 0
                    Date: 2019.09.02
                    Time: 00:00:59

[cliffcoggin]

Perhaps I am misreading the data but it appears to show that the last regeneration was 556045 km. ago. Whether that is related to running on petrol or not I have no idea.

[johnstables]

Hi Cliff,

The figure was in meters so converted to Km then to miles so 345 miles since last regen which sounds about right, I'll have VCDS early this week so hopefully I can do a forced regen to get the Soot levels down and do some digging to see where I go next .

 

Thanks, John

 

[cliffcoggin]

Well m is the standard abbreviation of metres which makes more sense, but the text distinctly states kilometres.

As for the rest of the report. I don't see that it tells you anything you didn't already know i.e. the engine is making lots of soot. What it does not tell you is why. It would be too much of a coincidence if the problem was unrelated to running on petrol, so you need to examine and possibly test the fuel system from pump to injectors. I doubt that the average home mechanic would have the equipment to do that as I fancy it would need flow testers and and injector measuring tools. In fact I wonder if even Audi main dealers would be able to do that, or whether they would simply renew parts in turn until the fault disappeared. I frankly don't know what to advise except to consult a diesel specialist.

[cliffcoggin]

John.

There is a Youtube channel by a John Cadogan that I regularly watch and by chance I happened on this video on DPFs. It may give you some hints on what is causing the frequent regenerations. Be warned, his language is satirical and often laden with expletives, but he is very knowledgeable. In essence DPF problems can be caused amongst other things by:

-inlet air leaks,

-faulty injectors,

-insufficient sustained high speed operation,

-the wrong oil.

https://www.youtube.com/watch?v=-bOlDFFhuPM

 

[johnstables]

Thanks Cliff,

I'll watch the youtube video, I think your right that without expert knowledge my local garage or Audi dealer would be replacing things bit by bit, I'm picking up VCDS from the post office today so hopefully i'll be able to force a regen to completion at least and think about my next steps.

John