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

**kenmurray** · 09-12-2012,12:04 AM

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** · 09-12-2012,12:05 AM

Change the fuel filter and get it scanned with vcds

**kenmurray** · 09-12-2012,12:58 AM

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

**niall campbell** · 09-12-2012,03:14 PM

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** · 10-12-2012,11:05 AM

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** · 11-12-2012,12:48 AM

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** · 11-12-2012,01:00 AM

Originally Posted by kenmurray

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

Free updates, email support, etc,etc...

**kenmurray** · 26-12-2012,07:21 PM

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

**JimC64** · 27-12-2012,12:54 AM

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** · 06-01-2013,06:45 PM

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 ,