BMK 3.0 TDi hunting erratic idle revs ( Have I got the most lemon A6!!! )

[c4a5er]

good luck gupsterg, if anyone deserves a result you do mate!

[gupsterg]

So this was how Friday morning went:-

i) got to dealer, handed TPI, adviser apologised, we will do coding straight away...

ii) got car back, scanned coding 0011372 like TPI suggest to do... check MVB 72-77 injectors look further down the - xx ms range

iii) start her up again erractic revs... let her run until they smooth out by themselves

iv) move out of car park, see plumes or should say smoke screen of white smoke behind me in rear view, when I mean clouds they were literally going higher then the roof and thick... so I thought take her for a drive and turn her off/on and see what happen...

v) So park up in another car park, wait for few minutes, start her up all AOK no erratic revs, no smoke ...

vi) Went to several locations which I need to go to all AOK
vii) return home rejoice car is fixed my wife breaths sigh of relief

viii) she takes kiddies for outing, return smiling car AOK

ix) late evening take family meal out... start with mild erratic revs .... return journey home erratic revs@start

x) start this morning return to shaking engine/erratic revs

xi) disconnect MAF all AOK

SO has car after ECM software update relearnt something which is causing the issue?

I have checked injector adaptation in module 01 and the values are correct... Link:- 3.0l V6 TDI (BKS/BMK/BUN) - Ross-Tech Wiki

Below is data concerning injectors...

	May	June	Oct	Nov 1	Nov 3
ECM SW	4F0 910 401 L	4F0 910 401 L	4F0 910 401 L	4F0 910 401 A	4F0 910 401 A
CODING ECM	0011772	0011772	0011772	0000000	0011372
MVB
72	-28.0 ms Time Corr. -12.0 ms Time Corr. -6.0 ms Time Corr.	-36.0 ms Time Corr. -8.0 ms Time Corr. -4.0 ms Time Corr.	-44.0 ms Time Corr. -16.0 ms Time Corr. -4.0 ms Time Corr.	-36.0 ms Time Corr. -12.0 ms Time Corr. -4.0 ms Time Corr.	-36.0 ms Time Corr. -12.0 ms Time Corr. -4.0 ms Time Corr.
73	0.0 ms Time Corr. -4.0 ms Time Corr. 0.0 ms Time Corr.	-2.0 ms Time Corr. -2.0 ms Time Corr. 0.0 ms Time Corr.	0.0 ms Time Corr. 0.0 ms Time Corr. 0.0 ms Time Corr.	0.0 ms Time Corr. 0.0 ms Time Corr. 0.0 ms Time Corr.	0.0 ms Time Corr. 0.0 ms Time Corr. 0.0 ms Time Corr.
74	-14.0 ms Time Corr. -4.0 ms Time Corr. -2.0 ms Time Corr.	-14.0 ms Time Corr. -2.0 ms Time Corr. -2.0 ms Time Corr.	-10.0 ms Time Corr. 0.0 ms Time Corr. 0.0 ms Time Corr.	-6.0 ms Time Corr. 0.0 ms Time Corr. 0.0 ms Time Corr.	-6.0 ms Time Corr. 0.0 ms Time Corr. 0.0 ms Time Corr.
75	-20.0 ms Time Corr. -8.0 ms Time Corr. -4.0 ms Time Corr.	-14.0 ms Time Corr. -2.0 ms Time Corr. -2.0 ms Time Corr.	-14.0 ms Time Corr. -6.0 ms Time Corr. 0.0 ms Time Corr.	-14.0 ms Time Corr. -2.0 ms Time Corr. 0.0 ms Time Corr.	-10.0 ms Time Corr. -2.0 ms Time Corr. 0.0 ms Time Corr.
76	-30.0 ms Time Corr. -16.0 ms Time Corr. -12.0 ms Time Corr.	-26.0 ms Time Corr. -16.0 ms Time Corr. -8.0 ms Time Corr.	-34.0 ms Time Corr. -20.0 ms Time Corr. -12.0 ms Time Corr.	-30.0 ms Time Corr. -16.0 ms Time Corr. -12.0 ms Time Corr.	-30.0 ms Time Corr. -16.0 ms Time Corr. -12.0 ms Time Corr.
77	-34.0 ms Time Corr. -18.0 ms Time Corr. -6.0 ms Time Corr.	-38.0 ms Time Corr. -14.0 ms Time Corr. -8.0 ms Time Corr.	-46.0 ms Time Corr. -18.0 ms Time Corr. -16.0 ms Time Corr.	-50.0 ms Time Corr. -18.0 ms Time Corr. -16.0 ms Time Corr.	-46.0 ms Time Corr. -18.0 ms Time Corr. -16.0 ms Time Corr.

At the moment I am feeling inclined to change MAF... are injectors also something to get checked by a workshop?

Again I feel so bad virtually for a whole day the car was like how it should be and MAF was connected at the time...

So what has made it go bad again

[gupsterg]

Does anyone know if the MAF is hot wire or hot film on the A6?

At the moment raining... so doing swotting

[sparker]

This any good to you?

Audi A6 C6 (4F) 3.0TDI MAF Mass Airflow Sensor | eBay

Doesn't have any part details but you could ask.

Description says it's as new, just used to find out if the MAF sensor was at fault!

Out of interest, why was the new software version an older one? 4F0 910 401 L to 4F0 910 401 A.

I can't help with any of this but ross tech wiki does say it learns and corrects the injectors for wear so maybe that is what it has done.

£20 for a maf sensor might be worth a punt??

All the best

[gupsterg]

Thanks Just bought it... I've been searching by P/N...

That one is made by DENSO DMA 0210... Link:- Denso Catalogue

Original one in car is by Hitachi... P/N 059 906 461 K ... EuroCarParts had a HÜCO/Hueco one at £140... Link:- HÜCO Automotive GmbH



This is what I understand about ECM software...

i) TPI 2008810/2 relating to "Fluctuating engine speed after start" state SVM action... Techie plug car in do relevant code via VAS...

ii) TPI does not state adaptations need to be done so either VAS machine note these and add after update or like when I do firmware updates on PC kit depending on type of update/size certain info is retained...

iii) From when I've looked at software sometimes the rev ie last letter is to denote what it supports not a indication of older/newer hence the code 0011772 was not accepted by the new ECM software... but 0011372 is...

Below is actual photo of my ECM... so what software p/n & rev I had before update was its original one...



iv) Now when I had issue with my J519 (Link:- Thread) I investigated software updating at home... I was able to get hold of flash discs,etc... hardware was what I lacked... now this is something I may look into again... it would be great to know what the coding in the ECM relates to as VCDS does not show a helper box... the coding is not about the type of glowplug IMO as the SVM code for bosch/beru ie ceramic/metal glow plugs is different so that would mean different ECM software P/N & rev possibly... again if I could get in to doing flashes myself I may gain understanding what coding does and P/N & rev of software...

Honestly mate thanks for suggestions/support/help and every other contributor

My post count does not in any way mean I am a know it all of VAG/mechanics... I'm just an owner...

The injectors is what I've been thinking as well... it could well be the type of wear/fault/rev of injectors I have do not follow a TPI or another's symptoms...

£20 for a maf sensor might be worth a punt??

Yep I agree... you see car run fine without MAF... but MVB's seem IMO to suggest MAF is functioning AOK... but when MAF is disconnected two things (AFAIK) are happening the EGR system is switched off plus injection timing/fuelling/etc is using ECM values/different method of calculations...

So does that mean injectors work AOK with values from ECM without MAF... I have not gained enough knowledge to know this... so tomorrow or until ebay MAF come will try MVB without MAF connected...

[OddBallBoy]

Must admit that much of the techy stuff in this thread has gone over my head but I've been following it as I really feel for you Gup. Hope the MAF makes a difference and that you get to the bottom of things soon.

[gupsterg]

Most of the stuff is how modern engines have evolved to... I never knew any of this stuff... it is not as technical as it may seem...

I never knew the difference between a supercharged car and a turbocharged car until now... I never even knew the turbo has two sides ie the fresh air/exhaust side... I thought it just worked

I still am not as technically proficient as maybe I need to be but will give it a damn good go a close friend who I rely on always says " A human has designed (x) and made (x)..."

I've just understood how the modern throttle system works... seeing how my throttle body had an issue I thought it was the fix... how wrong I was...

These were a good read besides other stuff I've been swotting up on...

Link:- HowStuffWorks "Top 10 Improvements in Engine Design"

Link:- HowStuffWorks "How Superchargers Work"

Link:- HowStuffWorks "How Turbochargers Work"

Link:- Audi turbochargers with variable turbine geometry - YouTube

Link:- HowStuffWorks "How Exhaust Heat Recovery and Recirculation Works"

Link:- Intercooler - Wikipedia, the free encyclopedia

Link:- HowStuffWorks "How Electronic Throttle Control Systems Work"

Link:- How a TDI engine is made and assembled on Audi Q7 TDI - YouTube

Some of the stuff above explains principles... helped my to gain more insight... still need to learn more

A great video on injectors IMO...



Injector bench test video Link:- Bosch Piezo TDI Diesel Fuel Injector Common Rail (2000 bar!) Bench Testing... - YouTube

No car I've had in xx years has made me do so much to it or been a crash course in how it is put together or works...

Generally servicing was quite easy/standard... when I did retros it sort of gave me insight into coding/modules,etc... then problems like the rear washer issues (pipework/carpet & interior removal/motor) meant you suddenly could visualise how when the car is rolling down the production line it is put together... you can also see how on a production basis they have to make elements the same then add extras for different specs,etc...

Now I feel I can understand the complexities of modern cars... you've got mechanics/electronics/software/coding... compared to classic/retro cars the complexity of a modern car is huge... to achieve power/emissions/efficiency/features...

Now you can see clearly from my recent visit to Audi dealer... some of the techs are just following a computer program ( Guided fault Finding ) the classic mechanic is disappearing IMO...

I have been extensively researching what to do if I decide sell or P/X Zesty the A6 as really can't take another hit like this on motoring.... and there seems no easy answer...

I have a friend who runs a taxi business... they have 200 cars on their books... I was talking to him about my predicament he said a Mondeo (2010) they have has been in 22 times to Ford... they replaced two turbos other expensive bits... the car was losing power... recently they replaced a intercooler pipe which fixed it... when he said to Ford how much did you spend on fault diagnosis they reckon several thousand £££... luckily he was covered by warranty... he has many stories...

[OddBallBoy]

I'm old school mechanical - I like to be able to see or at least visualise how something works. I feel up to pretty much any mechanical job as long as I can take my time over it (though I'm thinking of getting Crasher to do my cambelt when it's due in 5/6k as I wouldn't want to get that wrong!) and have done engine swaps, gearbox swaps, everything and anything suspension and brakes wise and plenty of gas welding over the years. It's a very satisfying feeling when you sort something yourself for a fraction of the cost of a professional doing it.

It's the electronics in modern cars I'm not so keen on. I've got a cheap code reader for my '97 Passat and that has proved really useful at times but I think if and when I get something else, and I have been tempted on numerous occasions, I'll stick with VAG and make sure I then get vcds. But the conversations you and A8 in particular have been having do make me think I should keep my old Passat going as long as I can - she's got nearly 203k on her now but overall been very reliable still going strong, should have another couple of years left in her yet. Just want a bit more power and a nicer soundtrack... And a 2.5tdi '03/'04 A4 Quattro Avant does look so appealing... Not the best of engines from what I read though so don't know what I'll end up with.

Always been a bit of a Landrover fan too but couldn't afford to run one daily. Maybe I should go Zollaf's route, get myself an 80 Tdi Avant as a daily runner (I've always loved estates since one of the first of my Dad's cars that I can remember, a Triumph 2.5pi estate, and I think the 80 is one of the most timeless designs ever) and a tax free Landrover for fun and winter. We shall see...

Thanks for the links, looks some interesting stuff there. And truly my best wishes for Zesty; don't think I've ever felt for someone as much car-wise as I do you with her as you obviously love/hate her so much.

Cheers,
Dave

[gupsterg]

Thank you for the support and understanding my predicament... I will reply to your post via PM...

One of the things that really shocks me is how Dialynx dealt with my car and their after care ( Link:- Dialynx – Home )... this was where the chain rattle issue was resolved...

There is some info in this post about some of the stuff they did wrong Link:- BMK 3.0 TDi hunting erratic idle revs ( Have I got the most lemon A6!!! ) - Page 3

You would not believe that on the drivers side headlight the bulb cover had some clips broken on the lower part, I discovered this when doing the adjustment of the headlight within the body after they fitted them wrongly.... the cover is about £25, so you can see if I was paying them £(x)K for work another £25 would not have blown the budget... they never even advised on pick up... I don't believe they broke the cover... I think because it is located behind air filter housing I never noticed it... when I did air filter I never noticed it as the top part fitted AOK... but when they removed headlights from chassis that cover would have fallen off just like it did when I removed them...

They creased the leather on the headrest by placing an object in the passenger rear footwell and then folding the seat down... when I complained the owner Keith Murray said its a design issue with folding action... I thought any person would know that if you place an object in the footwell and fold seat down on it and head rest is in contact with it for about 10 + days it will crease... I gave the car fully washed/waxed/cleaned inside and out, we walked around car together at booking owner Keith Murray commented how clean car was... and how clean engine was... when they removed engine and transmission him and his colleagues said it's one of the cleanliest engine/gearbox without leaks they'd seen I also agreed and that's what's made me keep trying with this car...

I had two attempts at talking to him about issues from the work they did both resulted in very rude comments from him, I emphasised I did not want money just answers, maybe an apology... my friends who know me and how I keep the car said you've got so many photos of the car and it's state before going in you should take it to court... I said I really have not got the time... successfully I have stopped 3 - 4 people I know not to go there...

You would not believe how much research I did to evaluate if I should get chain rattle done... I was gonna go to Crasher to get work done i) as forum sponsor ii) as reputation so good... I felt Dialynx had such a good reputation and close to me to give aftercare... I also thought if Audi charge £4K then Dialynx quote £1.5-£2K I can get loads of extras done and this can be one of those cars that you see people driving around which are old but so sound...

Before booking owner Keith Murray was so understanding and accommodating, I explained I needed access to car for my knowledge and help other forum members with my experience and possibly recommend them, I never took the biscuit with this access (10-15 mins it took me more time to get there), some days I never went, I wanted them to crack on...

I was very frank when I booked car in that I wanted it thoroughly checked... I even stated I had a large budget and just please check car meticulously as I do not want repeat issues or if you see some thing preventative that need to be done please do it... I was very clear that I understood the process and this was best time to do stuff as engine and transmission out...

I even pointed him to the thread about the injectors before booking in Link:- A6/C6 injector PROBLEM - Replacement/refirbished injectors possible? - Page 2

I noticed when going to view the engine that the AUX belt tensioner was showing signs of a leak... I asked him to change that and the AUX belt (they looked original)... he said the tensioner is providing enough tension I said Keith how much are parts? he said about a £100 and maybe couple of hours labour... I said if in x time after getting car back that belt or tensioner goes how would you replace... he said we would need to take bumper off, move rad forward,... I said then labour would be more then parts he said YES... at that point from the feeling I got from him towards my suggestion I decided not to give anymore and just let him finish as I felt if I made anymore I would end up putting engine/transmission in my VW Crafter and towing the chassis home!

You would not believe there was a time of two weeks between ringing to book and giving him car... even then he moaned that he needed to get my car off the ramp quickly... I thought I'm paying you, I advised I need bits check and done and now your telling me you have more work coming in and need to get it out the door... if you gave me a two week lead time and I waited can't your other customer wait like I did to get their car in your workshop...

The exhaust tips were also misaligned on car... I found cable ties which they had cut to remove harness in the engine bay... the whole thing was sloppy... I'm just glad that mechanically they did sound job and there are no leaks from the work they did... even though my experience was not great I paid promptly on the day of collection, in full, never complained... if I do work I wanna be paid so I treat people how I want to be treated... once I'd had car for a day and complained it fell on the the most deafest of ears IMO...

But never again would I go there... when I saw him in Audi driver this month I felt so livid and it brought it all back!

Dialynx Performance = NOT GOOD IMO

Why I never highlighted this before is I felt his reputation is vast against mine... but recently a friend when I was showing him the article in the Audi driver magazine he said you should tell people as it is your experience and not a lie...

[gupsterg]

Ohhh my god.... not only did MoonMonkey ( Link:- Piston heads thread ) have the lumpy idle issue but the ebay seller as well (Just got an email to some queries I sent)....

My car had a very lumpy idle which I tried to fix with a new throttle body and a new MAF - neither of which cured the problem.

There was 1 then 2... now 3...

MoonMonkey is not the ebayer seller as we have been communicating via email...