2008 A6 2.0 tdi bre , Misfire , hesitation , lack of power

[kenmurray]

2008 A6 2.0 tdi bre engine , hesitation , slight misfire, lack of power above 3000rpm driving 3rd 4th 5th 6 th gear , higher the gears more noticeable , won't rev out , no fault codes , fuel filter replaced 30k miles ago timing belt changed 5k miles ago , timing marks rechecked ok , new air filter , static vehicle the engine revs out ,

[Guest 2]

Change the fuel filter and get it scanned with vcds

[kenmurray]

Will change filter thanks in advance post back , is vcds Scanner available to purchase ? , regards , ken

[niall campbell]

check mass air flow meter as well. Below certain revs , the car will drive fine ; and then in higher revs it fails leading to loss of power as your feeling. It will probally reset itself when you switch ignition off.

[bloostar]

Is there any 'whooshing' noise in the cabin from the passenger side under acceleration as well? Same symptoms occurred with mine a few years back and it turned out to be the intercooler. Oild around the fuelfilter is another sign, with intermittent power, misfiring and free revving ok in neutral.

[kenmurray]

No whooshing noise , no oil leaks , car has only done 85k miles , timing belt was replaced at 80k by myself , rechecked marks ok , tks

[gupsterg]

is vcds Scanner available to purchase ?

Bought mine from Gendan... great product, invaluable to a VAG owner IMO... Link:- http://www.gendan.co.uk/product_VCHU.html

(http://www.gendan.co.uk/product_VCHU.html)Free updates, email support, etc,etc...

[kenmurray]

The fuel filter was partially blocked, replaced it and that fixed the problem , thanks to all for their replies

[JimC64]

Hey Ken, I'm intruiged by your post and have similar issues I believe on my 2007 A6 2.0 Tdi remapped.

It generally seems to happen in higher gears but at lower speeds and there is a juddering / shaking that can be felt, its quite violent and I usually change down to alleviate this. I have no codes at all and the car otherwise seems to run fine.
One thing I did notice today though as I was on the motorway I decided to open her up to loosen the cobwebs and she seemed a little underpowered?

As with you the car has been serviced recently including new air filter, oil filter + oil change as well as fuel filter.

I'm hoping that it may be something as simple as changing the fuel filter but don't know if I hold out much hope of it not being something more serious.

It's going in to Audi on Friday for a road test and I may get them to scan it too and see what it shows up, perhaps replace the fuel filter. I've had thoughts of DMF or injectors running through my mind so I'm a little concerned to say the least.

[kenmurray]

Yes the fuel filter was partially blocked , as I blew through the supply line on new filter and compared to old filter , definate difference was noted , changed the filter anyway and it drives like normal no with no hesitation or misfire , it's the cheapest and best option to replace the fuel filter , any blockage will starve tandem fuel pump of adequate amounts of fuel thereby starving the injectors of correct quantity of fuel on demand ,

[martliz]

hi new to this just wondered if you resolved your promblem our a6 has the same issue thanks mart

[martliz]

hi new to this just wondered if you sorted it ? our 08 a6 bre engine code has the same issue.thanks.

[kenmurray]

I replaced the fuel filter and it resolved the issue, hope this helps

[JimC64]

Hi all,
I had my car in at Audi today, as some of you know I've been suffering with hard starts / poor cold starting that gives a 15-20 secs jerky feel, quite scary until she settles down with a light rev to 2000 rpm.

I've also had a judder that appears when in high gears and at low revs, the car judders quite violently and I've been advised to replace the in tank fuel pump at over £550 by Audi
This can be driven around / avoided and rather than try to push through it, I've always came off the gas and changed down, no issues.

Well, with no other recomendations, I decided to try changing the fuel filter and also the glow plugs to see what effect if any that would have, couldn't hurt so lets see......

Please see glow plugs detail below...

NGK CZ301 7V K6Z8C
VW AG N10579803

http://i140.photobucket.com/albums/r38/jaycam0802/glowplugs2_zps16221da9.jpg

http://i140.photobucket.com/albums/r38/jaycam0802/glowplugs1_zps6a202fa0.jpg


I'm no expert on glow plugs but having read a lot about them, they look to be an item that aren't either necessarily good or bad, but they weaken and lose their effectiveness over time. At over 101k miles perhaps mine are due for replacement I thought, so lets see....

Anyone with any glow plug knowledge or experience please feel free to chime in and advise what looks to be good or bad in the pics above, it could be quite helpful for others.

The other item was the fuel filter.

My car is looked after and anything she needs she pretty much gets. Audi recomend filter filters be changed at 40k miles
I used to cover stellar miles, mainly motorway and around 50k - 70k per year, this has now changed to around 10k-15k and mostly stop/ start around town.

My last filter was changed at 79583 miles and I'm currently at a little over 101k miles, so its done just under 22k miles, so should be good right?
WRONG!!

Mines was BLACK and contaminated with oil

I asked Audi to keep the old fuel filter for me, but they didn't, they did one better and made me a video to share with you all showing the fuel that came out.

See link below....

You will need a pin to view, please use the following bearing in mind its case sensitive
ec3cf76e

Click here (http://audicam.audi.co.uk/customer/44853/cfb2065e1197e2ab/44854/44855/1)


You can clearly see the black covering of oil in there.

I haven't had any dodgy fill ups as far as I'm aware? I used to use Tesco fuels, but changed some time ago ( around 9 months ) and now only use Shell Vpower diesel

Driving home from the dealers I noticed instantly a huge improvement in pulling power, she was ready n eager all good to go, pulling like a train, always a good sign.

I did try and check several times for the jerky / judder, lumpiness and it seems to have disappeared . It may be too early to tell so I will watch for any signs of this and report back as necessary over the coming days / weeks / months.

As for the glow plugs?
I'm not 100% sure if they've made a difference tbh.......Again, I'll check and report back on this

At a cost of £265.93 its all good as far as I'm concerned at the moment and money well spent.
Thanks Stirling Audi

Audi advise that there may be an issue either with my injectors / tandem fuel pump that could be causing the oily fuel as seen in the filter and I know thats £££ to fix........I'll be doing further checks.

The thing is I actually had all 4 injectors and the tandem pump replaced under warranty some time ago in 2009 due to issues I was having at that time. Should these need doing again at any point and as a customer who has bought the car from new, had all service and warranty work done there, also own a Passat I'll be speaking to customer services and looking for a major contribution, if required.

Hope this post is useful and helps someone else

Thanks

Jim