Audi A8
V8 diesel with 283 kW. Mighty eight-cylinder diesel with enormous torque of 850 Nm. Exclusive and very torquey, but expensive to service.
Smooth multi-cylinder — effortless touring
385 hp 4.2L with pleasant refinement. Relaxed cruising, no sporting ambitions. Budget for the known weak points.
Engine Weaknesses 5
Failed injectors are a known problem on the 4.2 TDI V8. With 8 cylinders the cost of injector replacement is correspondingly high. Fuel ingress into the oil from dribbling injectors damages the engine.
Symptoms: Stumbling and hesitation on cold start, rough idle, dark smoke on cold start, fuel smell in engine oil
The 4.2 TDI V8 has a complex timing chain arrangement. Chain replacement reportedly costs around €6,500 at Audi and €3,500–4,000 at an independent shop. Oil change interval is critical for chain life.
Symptoms: Rattling metallic noise on cold start, engine check light with camshaft fault, worst case engine damage
The 4.2 TDI V8 with bi-turbo shows turbo bearing damage at high mileages. The installation position and number of turbos makes repairs very labour-intensive. Short trips and immediate shutdown after full load increase the risk.
Symptoms: Whistling or grinding turbo noises, power loss, elevated oil consumption, blue smoke from exhaust
The EGR system on the 4.2 TDI V8 with 8 cylinders is particularly prone to coking. Frequent urban use prevents complete regeneration and causes deposits throughout the intake tract.
Symptoms: Power loss in the mid-range, smoking under load, increased fuel consumption, engine warning light
The ZF Tiptronic in the A8 with 4.2 TDI shows shift problems and is described as 'underdimensioned'. ZF transmission fluid change every 60,000 km is mandatory, despite Audi declaring it a 'lifetime fill'.
Symptoms: Jerk on gear changes, delayed engagement, torque converter locking too early or too late, limp mode in severe cases
Vehicle Weaknesses 13
The adaptive air suspension on the A8 D4 is a well-known money pit. Air bellows become porous, the compressor runs non-stop and overheats. Repairing all four corners costs several thousand euros.
The 4.2 TDI V8 in the A8 D4 has a timing chain that is prone to premature wear when neglected. A break causes severe engine damage. Replacement requires complete engine removal.
The 4.2 FSI V8 has four timing chains with phenolic resin guide rails that become brittle with age. Neglected oil changes risk chain skip.
Turbocharger bearings can wear and bring the turbine wheel into contact with the housing. Audi recalled around 26,000 vehicles in 2022.
Leaking air bellows cause the vehicle to sink and force the compressor into continuous operation until it fails. Front and rear are equally likely to be affected.
The MMI multimedia system stands out from 60,000–100,000 km with frozen screens and unresponsive controls. Multiple control modules can be affected.
The ZF 8-speed automatic shows harsh gear changes and gear selection problems at high mileage. Regular oil changes (every 80,000 km) are critical.
The MMI multimedia system is known for total failures caused by overvoltage damage after battery replacement or moisture damage to the Bluetooth control module.
The rubber-metal bushes of the front control arms on the heavy A8 D3 show significant wear at high mileage.
Front and rear control arm rubber bushes go soft with increasing mileage. The A8's considerable weight accelerates wear.
The 6-speed Tiptronic shows harsh gear changes at high mileage. A gearbox oil change often resolves the problem.
With increasing age the driver's side window regulator switch block on the A8 D3 frequently fails. The switch block must be completely removed for replacement. Pixel failures in the instrument cluster and screen faults are further typical age-related symptoms.
Almost all A8 D3s show worn and peeling soft-touch surfaces on light switches, trim panels and control knobs. The coating detaches in strips, leaving a sticky surface that is visually badly affected.
Reports & Tests
124 owner complaints filed with NHTSA (2010–2017). Most reported: Engine (78), Other (13), Fuel System (12).