Six-figure luxury at a fraction of the price
The Audi A8 is Audi's flagship luxury saloon, competing directly with the Mercedes S-Class, BMW 7 Series, and Jaguar XJ. It attracts buyers who want cutting-edge technology and understated prestige over the more ostentatious Mercedes or sporting BMW. On the used market it represents extraordinary value — a car that cost £80,000+ new can be bought for less than a new supermini — but running costs remain firmly at the luxury end.
We track 5 known issues across the Audi A8 range, including 1 rated as safety-critical. Knowing which variants and configurations to approach with caution can save you from expensive surprises after purchase.
Found a Audi A8? Enter the reg to see which of our 5 known issues apply to that exact car, plus full MOT history and mileage checks.
D2 (1994–2002) — Engine options included the 2.8 V6, 3.7 V8, 4.2 V8. We track 2 known issues on this generation, with 1 classified as significant. The most significant concern is Brake hose deterioration (£200–£400 to address).
D3 (2003–2009) — Petrol options included the 4.2 FSI V8, 6.0 W12, with 3.0 TDI V6, 3.0 TDI V6, 4.0 TDI V8, 4.2 TDI V8 on the diesel side. We track 2 known issues on this generation, with 1 classified as significant. The most significant concern is Brake hose deterioration (£200–£400 to address).
D4 (2010–2017) — Petrol options included the 3.0 TFSI V6, 4.0 TFSI V8, 5.2 FSI V10, 6.3 W12, with 3.0 TDI V6, 4.2 TDI V8 on the diesel side. Our database flags 3 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Timing chain issues (£1,500–£3,000 to address).
The 4.2 TDI V8 engine uses timing chains with hydraulic tensioners to drive the camshafts. The chain tensioners lose pressure due to worn seals or blocked oil galleries, allowing the timing chains to slacken and jump teeth on the sprockets. This changes valve timing and can cause piston-to-valve contact in severe cases. The V8 configuration uses four timing chains, and failure of any one chain affects engine timing. Extended oil change intervals and low oil levels accelerate tensioner wear.
If timing chains jump multiple teeth, piston-to-valve contact can occur, requiring complete engine rebuild. Even minor timing chain stretch affects fuel economy and emissions. Replacement requires engine-out work on the V8, typically costing £4,000-£6,000. The car should not be driven if significant chain rattle is present.
Listen carefully for a rattle or ticking noise from the engine on cold start — this is the most common early sign. Ask for evidence of chain replacement in the service history. On higher-mileage cars without documented replacement, budget for preventative work.
The D4 A8's adaptive air suspension uses complex electronically-controlled air springs, height sensors, and a central compressor system. Air springs develop leaks in their rubber bellows, particularly where the spring meets the upper mount. The compressor works harder to maintain ride height, leading to overheating and eventual failure. Height sensors become contaminated with road debris, causing erratic ride height control. This is a characteristic high-mileage failure mode on luxury air suspension systems, with repair costs that often exceed the car's depreciated value.
A failed air spring or compressor leaves the car sitting low on one or more corners with poor ride quality and potential tyre wear. The car remains drivable but handling is compromised. Complete air suspension replacement typically costs £3,000-£5,000. Many owners convert to conventional coil springs at £1,500-£2,500.
Listen for knocking, clunking or rattling over bumps during the test drive. Inspect the underside for corroded or cracked suspension components. Check the MOT history for suspension-related advisories, which often predict future failures.
Flexible brake hoses on older A8s deteriorate with age, developing surface cracking, internal swelling, or complete splits. MOT data shows this model fails at 6.8x the fleet average for brake hose condition, particularly on high-mileage petrol variants. The flexible sections connect the rigid brake lines to the brake calipers and must flex as the suspension moves. Age-related rubber degradation is accelerated by brake fluid contamination and heat cycling.
A split brake hose causes sudden brake fluid loss and potential brake failure - this is a dangerous safety defect. Internal hose deterioration reduces braking effectiveness and causes spongy pedal feel. Brake hose replacement costs £150-£300 per corner but must be treated as urgent if deterioration is found.
Check brake disc condition for lipping or scoring. Test braking at moderate speed for pulling to one side or vibration through the steering wheel. Review MOT advisories for brake-related items.
The 6.3 W12 engine uses 12 individual ignition coilpacks, one per cylinder. Heat cycling and vibration cause the coilpack windings to break down, leading to weak spark or complete ignition failure on that cylinder. Failed coilpacks cause misfiring, rough running, and increased emissions. The W12 configuration makes diagnosis more complex as cylinders are arranged in a tight V formation. Coilpack failure is progressive - typically one or two fail initially, with others following over time.
A single failed coilpack reduces power and fuel economy but does not prevent driving. Multiple coilpack failures cause severe rough running and potential catalyst damage from unburnt fuel. Individual coilpack replacement costs £50-£100 but accessing them on the W12 requires significant labour time.
Check for misfires, rough running or hesitation under acceleration. Ask when spark plugs and coil packs were last replaced. A diagnostic scan can reveal stored misfire codes that may not be obvious during a short test drive.
The A8's front suspension uses multiple rubber bushes in the control arms, anti-roll bar links, and subframe mounts. These deteriorate with age and mileage, causing increased play in the suspension geometry. MOT data shows this model fails at 10.3x the fleet average for suspension bush wear, particularly affecting 4.2L petrol and 3.0L diesel variants. The aluminium space frame construction places different stresses on bushes compared to steel-bodied cars.
Worn suspension bushes affect handling precision and can cause accelerated tyre wear due to incorrect wheel alignment. The car remains safe to drive but MOT failure is likely once wear becomes excessive. Bush replacement typically costs £300-£600 depending on which bushes require changing.
Listen for knocking, clunking or rattling over bumps during the test drive. Inspect the underside for corroded or cracked suspension components. Check the MOT history for suspension-related advisories, which often predict future failures.
For the full breakdown of all 5 tracked issues with repair costs, see the Audi A8 common problems page.
Based on 70k real DVSA MOT tests, the Audi A8 fails more often than average on several items. The biggest outlier is headlight fault at 43x the fleet average, followed by parking brake inefficient (15x).
When viewing a specific car, check its MOT history for recurring advisories in these categories. See the full Audi A8 MOT failure breakdown for data at every mileage point.
Routine servicing (oil and filter change every 10k miles) typically costs £120–£200 at an independent garage.
The bigger-ticket items to budget for include timing belt (£400–£600), air suspension compressor service (£200–£350).
See the full Audi A8 service schedule for every interval and cost breakdown.
The Audi A8 has some well-documented weak points, including 1 safety-critical issue that demand careful checking. The right example, properly maintained, can still be a sound purchase — but cutting corners on the pre-purchase inspection is not advisable. The D4 generation (2010-2017) is widely considered the most dependable A8 ever made, with 2011 and 2015-2017 models standing out. The 2007 D3 facelift is also well-regarded. Avoid 2003-2005 models (early D3 reliability woes), 2013-2014 (most recalls), and 2020 (first-year D5 teething problems).
Before committing, check the car's full MOT history, verify the service record is complete, and if possible arrange a specialist inspection. Enter any registration into our free report to see the complete picture.
Get Car Wise maintains a database of known mechanical issues for every popular car on UK roads, tracking the faults that owners, specialists and DVSA data reveal.
When you run a report on a specific Audi A8, we cross-reference the exact variant, engine and age against our database of 5 known issues. Combined with full MOT history analysis, mileage verification and DVLA data, you get a complete picture before viewing.
Enter the registration for MOT history, mileage verification, known faults for that exact variant, and a Get Car Wise Score.
This guide was compiled from independent expert reviews, DVSA MOT data, specialist workshops and our own database of 5 known Audi A8 issues. We are not affiliated with any source listed.