Audi A6 Avant (2005 – 2011) Review

• February 2005: New A6 Avant revealed
• July 2005
• February 2006
• June 2006
• December 2006
• October 2008

Reports of engine vibrations from 2.0 TDI manuals after around 30,000 miles, apparently caused by "melted injector seals" from using the wrong fuel.

Some readers have reported as little as 1,000 miles a litre of SLX oil (at £13 a litre) from the otherwise excellent 3.0 TDI.

Seemingly widespread problem with dual mass flywheels on A6 2.0 TDIs which causes stalling. These can start to separate and the clutch can fail by 45k miles requiring expensive (£1,200) replacement.

Another problem of 2.0 TDI PD 140 and 170 is failure of the oil pump. The oil pump is driven from a balancre shaft via a short hexagonal shaft. The peaks of this hexagonal shaft locate in six corresponding but minute grooves machined within the otherwise circular-bored oil pump drive shaft. Thus, the oil pump drive relies entirely on an interference fit of little more than 0.010" along the peaks of the hexagonal shaft. After about 50,000 miles, the shaft can round off, resulting in a totally destroyed engine and turbo, plus a bill of up to £9,000. If the danger is known and the oil pump is removed by the garage in good time, a new replacement pump will cost over £500, plus the labour etc to remove and refit it. However, it is also possible to save the old pump and modify the drive at a fraction of the cost of a new one. Many local machine shop already have numbers of these pumps in for such rectification, the drive shaft of each having been on the point of rounding off.

Fuel gauges suffer a fault of the needle stuck on empty when the tank is full (software upgrade required) and the parking brakes are intermittently not releasing, again requiring software upgrade.

Reader Chris Laming reports after 2 years and 43k miles with A6 2.7 TDI manual: "Rear door seal design fault allows muck from the road to badly soil the rear door surround even in a light shower. This particularly affects the inner wheel arch surface right next to the rear seat so clothes can easily get spoiled. Loose trim in one rear window surround and a surfeit of glue knackered the passenger vanity mirror from new. Floorpan and steering vibrate at speed, even on dead flat French autoroutes. I noticed this when the car was new so it's not as a result of speed bumps or anything like that.

My Audi dealer expressed surprise and balanced the wheels. It made no difference and it makes long journeys tiring. I get the same vibration through the gearstick when the car is stationary and ticking over so I think it's an engine/transmission set up issue. Stalls easily if pulling away in second. Steering too light. Probably the worst feature of the car from the driver's perspective - just not engaging enough. Locking wheel nut key is cunningly hidden underneath the towing eye in the toolkit. So well hidden that tyre dealers think you haven't got a key and send you away. Optional retractable tow bar: Simple design does the job but its electrics can be temperamental and it jams with road dirt."

Tip from Audi specialist: Sachs DMFs on 2.7 TDIs much less troublesome than the DMFs on 4 cylinder TDIs.

One reader's experience of A6 2.0TDI Multitronic: "I bought my A6 from Lincoln Audi with 5k on the clock today it has 112k. I have had problems with the car and spent over £3,000 in the past 6 months on DPF, into the garage 3 times before they gave up and changed it with no guarentee it would not happen again. Only last week Oil Pump Siezed and also took out Turbo. I was originally quoted £1600 for the turbo but after haggling and stating my case they charged me £770. the question is I paid £840 for the Oil pump with 10% goodwill. Perhaps I shouldn't complain but these cars should do at least 200k before major component failure thats why we customers pay all that extra money. Having collected my car today there was a note attached to the £2,022 bill stating that the dual mass flywheel is worn and should be replaced at a further cost of £1,099. My previous car was also purchased from Lincoln Audi and was an A6 2.0ltr Turbo Manual and after 15000 miles the Dual Mass Flywheel Seized up. Fortunately for me it was under warranty."

Timing chains of 3.2V6 petrol engines can fail under Longlife service regime, so much wiser to switch to 10,000 mile oil service intervals.

Complaint of repeated timing chain failures on 3.2V6 FSI petrol engine.

Swirl flap motor failure in both inlet manifolds of 2006 2.7TDI V6, and a quotation by the Audi dealer of £1,122 to replace.

Specific problem to the Avant: Screenwash pipe to the rear wash wipe can leak over MMI unit located behind a panel in the rearside of the load bay. Replacement costs £850 inc. VAT. There is an Audi TSB 92B8 to repair the washer hose, but this is only routinely carried out when cars are in Audi dealers for servicing.

(I have a 2007 Reg Audi 3.0 litre Quattro Avant Le Mans ( Chassis No WAUZZZ4FX7N130202 ) . It is serviced at an Independent Audi Garage , using Audi spares , purchased through Trade Parts Solutions . I understand this is an Audi/VWowned parts supplier to Audi aftermarket Dealers . At the beginning of March , I attempted to use the rear wash wipe , with little effect . The next time I entered the car the MMI was not working i.e. no Sat. Nav. , Phone , Radio or C.D. Upon examination I found that water had covered the MMI Unit , located in the nearside boot area . On taking the car to my Independent Dealer , he informed me that he had dealt with four such occurrences .I have since checked the Internet , and find this is a common problem . In my view this is a design fault . Why route a waterpipe over the MMI ? The Independent fitted a new MMI for eight hundred and fifty eight pounds inc. VAT . However , the radio speakers would only operate on one side of the car , as the component protection system had activated to minimise damage . This had to be reset by the Main Dealer , for a further seventy five pounds inc VAT . I contacted Audi customer service ( Nicola , 0800 699888 extn. 63387 ) , and was told that Audi were not prepared to compensate me , as the car was serviced outside their network . Despite the fact that the parts came from their subsidery . My point is , that for cleaning my rear window , I have I have incurred a cost of NINE HUNDRED and THIRTY THREE POUNDS , for what I believe is a design fault . This is strenghened by the Audi Garage doing a '92B8 Recall ' , repair to the washer hose , while they had the car . Why was this not done when they last had the vehicle , for an MOT , on 02/03/2011 ? I seem to recall that that E.U. rules allow me to service my car where I wish , as long as manufacturer's parts are used)

Usual oil pump failure in 60k mile four and a half year old 2.0TDI Avant, leading to turbo failure due to oil starvation. But because the car had been Audi maintained all its life, all fixed for £1,000, after contributions from Audi and the dealer.

Report of failure of engine of 2006 Audi A6 2.7TDV6 Avant at 204,000 miles. First thought to be an injector, but, after replacement, it failed again, thought to be the ECU.

Report of timing chain failure in engine of Audi A6 2.7V6TDI at 118,000 miles.