Audi A8
4.2-litre FSI V8 with 350 PS — direct injection without turbocharging in the A8 D4. Intake valve carbon build-up from FSI technology typical; timing chain guide rail fracture documented at very high mileage. Timing chain cover leak requires engine removal. Oil changes every 10,000 km, no Longlife intervals.
Sovereign power in the luxury class
The A8 D4 with the 4.2 FSI moves the aluminium saloon with impressive effortlessness — 0–100 in just under 5 seconds. The driving experience remains comfort and composure-focused.
Engine Weaknesses 8
The CDRA in the A8 D4 is considered a 'complex clockwork'. Timing chain cover leaks, engine removal needed for sealing. Guides and tensioners wear out. Particularly high repair costs in the heavy A8 due to labour.
Symptoms: Rattle on cold start, progressive noise, engine warning light, camshaft fault codes
Four camshaft adjusters on the CDRA wear due to low oil or extended service intervals. Rattling, fault codes and limp mode are typical. Very expensive repair in the large A8 engine.
Symptoms: Rattle on start, engine warning light, limp mode, power loss
Elevated oil consumption through valve stem seals and piston rings. In the A8 D4 with long service intervals, consumption is often noticed late. 1–2 L/1,000 km typical at higher mileage.
Symptoms: Oil level drops between changes, blue smoke on cold start or after overrun
FSI direct injection without valve washing creates carbon deposits. In the A8 D4, often used with a driver in urban traffic, this is particularly problematic. Power loss and increased fuel consumption.
Symptoms: Power loss, rough idle, poor throttle response, increased fuel consumption
CDRA water pump fails after 100,000–140,000 km. In a luxury saloon context, the labour involved is particularly expensive. Replace the thermostat at the same time.
Symptoms: Coolant loss, temperature gauge rising, coolant smell, overheating warning
The ZF gearbox in the A8 D4 needs an oil change every 60,000 km (not specified by Audi). Neglect leads to shift judder and gearbox failure. Typical repair savings with good service history.
Symptoms: Shift judder, jerking on pull-away, delayed gear changes, gearbox overheating
Timing chain cover becomes leak-prone with age. Sealing the cover requires engine removal and separation from the gearbox — an extremely labour-intensive repair on the A8 D4.
Symptoms: Oil loss at front of engine, oil puddles under vehicle, oil smell after driving
V8-typical ignition coil failures. 8 coils = increased statistical probability of failure. In the A8 D4, coils are less accessible than in smaller models.
Symptoms: Misfires, rough idle, hesitation, engine warning light with misfire code
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).