Fault File
All models / All cars / Saloons & estates / Audi A6

Audi A6

All generations and engines together · 101,905 MOT tests in the 2025 data · typical mileage at age 7: 80k

First-time failure at age 7
14.5%
Across 8,550 tests. The average across all tracked models is 19.5%.
Rank at age 7
44 of 239
1 = lowest failure rate among the models tracked.
Typical mileage at age 7
80k miles
Check the mileage view below; low-mileage models can look better by age than they are.

Generation

Split by first-registration year. Cars registered in a changeover year can belong to either generation.

How this model wears

Audi A6Class average, all tracked models

Known issues

Measured

Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.

What testers flag

Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.

Faults with the car itself

The rows that judge the model rather than its keeper. 39,653 tests in this band.

A suspension pin, bush or joint excessively worn
Advisory
11.7%class 5.9%
A shock absorber damaged to the extent that it does not function or showing signs of severe leakage
Advisory
2.8%class 2.3%
Engine MIL illuminated indicating a malfunction
Fail
2.1%class 0.9%
A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc
Fail
1.9%class 0.6%
A suspension pin, bush or joint excessively worn
Fail
1.6%class 0.9%
A transmission shaft constant velocity joint boot severely deteriorated
Minor
1.5%class 0.6%
A spring or spring component fractured or seriously weakened
Fail
1.0%class 1.4%
A suspension component excessively damaged or corroded
Advisory
0.9%class 0.6%
Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users
Advisory
0.9%class 2.0%
A spring or spring component fractured or seriously weakened
Advisory
0.6%class 0.0%

Wear, upkeep and luck

Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.

Tyre tread depth not in accordance with the requirements
Advisory
29.2%class 22.9%
A brake lining or pad worn below 1.5mm
Advisory
8.9%class 8.7%
A tyre seriously damaged
Advisory
7.6%class 13.4%
Brake disc or drum excessively weakened, insecure or fractured
Advisory
6.2%class 10.1%
Brake disc or drum significantly and obviously worn
Advisory
3.7%class 3.4%
Tyre tread depth not in accordance with the requirements
Fail
3.4%class 2.2%
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
Minor
3.1%class 2.0%
Child Seat fitted not allowing full inspection of adult belt
Advisory
2.8%class 2.2%

Unconfirmed issues

Reported

Owner folklore from forums and the motoring press. Most of it never shows up in an MOT, which is why this section exists at all.

Air suspension faults and one-corner sag

Partly in the MOT data

Cars fitted with the optional adaptive air suspension (common on Allroad and quattro models) can throw a suspension fault message, with one corner sagging overnight or the ride turning go-kart-stiff after 30-60 minutes of driving. It is usually a leaking air spring or a tired compressor, and it tends to surface from around 70-90k miles or once the car is 8-10 years old. The measured MOT data for this segment flags suspension as the standout fault category too, though the failure it captures (bushes, springs, dampers on the general test) is not exactly the same air-strut problem forums complain about. A leaking air spring alone runs to roughly £250-£450 a corner; a failed compressor is more like £500-£900.

Reported 70-90k miles on air-suspension cars · sources: Audi Owners Club forum, AudiWorld C7 platform forum, Audizine, r/Audi

3.0 V6 diesel and petrol timing chain tensioner wear

Emerging

The 3.0 TDI and 3.0 TFSI V6 in C7-era A6s (2011-2018) can develop a rattly, worn timing chain tensioner, most often flagged by a rattle on cold start-up that fades once oil pressure builds. Owners on Audi's own forums note the worst of it seems concentrated on pre-2015 build cars, and left unaddressed it can lead to a snapped or jumped chain and serious engine damage. A tensioner-only fix runs into four figures; a full chain kit with the engine apart is more like £2,000-£4,000, so any cold rattle is worth walking away from or getting inspected before buying.

Reported mostly on pre-2015 3.0 TDI/TFSI cars · sources: AudiWorld forum, PistonHeads, audi-sport.net

EGR clogging and limp mode after the diesel emissions fix

Emerging

Several 2.0 and 3.0 TDI C7 owners report that after having Audi's diesel emissions software update applied, the engine revs a little higher on light throttle and the EGR valve clogs with soot faster than before, occasionally tripping limp-home mode. It is not universal and Audi has not put out a public fix for the side effect itself, only for the original emissions issue, so treat it as something to budget for rather than a certainty. A new EGR valve and clean typically runs a few hundred pounds.

Reported on updated 2.0/3.0 TDI C7 cars · source: Honest John Audi A6 (2011-2018) carbycar page

Early 2.0 TDI PD dual-mass flywheel and oil pump wear

2.0 TDI PD manual (C6, 2004-2011) only

On the pre-2008 C6 with the pump-injection (PD) 2.0 TDI and a manual gearbox, the dual-mass flywheel is a known weak point, with failures reported by around 45,000 miles and a bill near £1,200 to replace. A rarer but much nastier fault is the oil pump drive shaft rounding off, which can starve the engine of oil and write it off entirely, a repair Honest John puts at up to roughly £9,000 in the worst cases. Common-rail diesels from the 2008 facelift onward are not affected by either issue.

Reported from ~45k miles on pre-2008 manual 2.0 TDI · source: Honest John Audi A6 (2004-2011) carbycar page

S tronic judder pulling away or in reverse

Automatics (S tronic) only

On C7 cars fitted with the S tronic dual-clutch automatic, owners report a shudder or judder when setting off from a standstill or engaging reverse, most noticeable once the gearbox is warm. It points to wear in the clutch packs or the mechatronic unit rather than anything that shows on a dipstick check. A full mechatronic replacement is an expensive job, commonly quoted in the £1,000-£2,000 region depending on parts and labour; manual and Multitronic CVT cars are not affected.

Reported on warm S tronic gearboxes · source: Honest John Audi A6 (2011-2018) carbycar page

48V mild-hybrid generator failures on C8 models

Emerging

The C8 (2018 onwards) runs a 48V mild-hybrid belt-driven starter-generator on most petrol and diesel engines, and owners on Audi's own forums and Reddit describe it failing outright and taking down the wider electrical system with it, sometimes with warning lights for steering or brake assistance appearing first. It is a young enough fault that mileage and cost data are thin, and Audi has not issued a public acknowledgement, so treat any 48V or hybrid-system warning light on a test drive as a reason to get the car properly diagnosed before buying rather than a glitch to ignore.

Reported on 48V mild-hybrid C8 cars, insufficient UK cost data yet · sources: audi-sport.net forum, r/AudiA6

Viewing one? Ask this

Built from the two sections above.

Watch the ride height for a minute after start-up on air-suspension cars. A corner that sits low and slowly rises, or a permanently stiff ride, points to a leaking air spring or dying compressor.
Start the 3.0 TDI or 3.0 TFSI stone cold and listen for a rattle for the first few seconds. A rattle that lingers well past idle settling is a sign of a worn timing chain tensioner, get it inspected before buying.
Rev the diesel gently from idle and watch for it hanging high or a warning light. Unusually high idle revs or a limp-mode light suggests the EGR is already clogging up.
On manual pre-2008 2.0 TDI cars, ask for service history showing the dual-mass flywheel or clutch. No record of replacement by 45-60k miles means it is probably close to failing.
On S tronic automatics, pull away gently and try a few reverses once the car is warm. Any shudder or judder means clutch pack or mechatronic wear, a costly repair.
On C8 mild-hybrid cars, cycle the start-stop system a few times in traffic or at lights. Repeated 48V or hybrid system warnings point to a generator fault worth diagnosing before purchase.
Check the MOT history for repeated suspension advisories across multiple tests. The same suspension item flagged year after year means it is being ignored, not fixed.

Others in its class

Same segment (Saloons & estates), best MOT record first. Compare before you shortlist.