Audi A8
Biturbo V8 with 338 kW and 48V mild hybrid in the A8 D5. Flagship petrol engine with cylinder deactivation and electric compressor. Exceptionally refined.
V8 BiTurbo — understated with bite
460 hp V8 combines comfort with track potential. Perfect camouflage for genuine sportiness.
Engine Weaknesses 5
Recall (campaign 21H7): oil strainer in the 4.0 TFSI V8 turbo oil supply clogs with carbon deposits. Affects 2013–2017 models. Vehicles from March 2017 have an improved strainer with coarser mesh.
Symptoms: Sudden engine stall during driving, engine does not restart after standstill, engine warning light, rough idle
The twin turbos of the 4.0 TFSI DDTA can fail completely from oil starvation (oil strainer) or bearing wear. Repair costs €8,000–11,000 at Audi. Preventive measures: shorter than manufacturer oil change intervals, let engine idle after motorway driving.
Symptoms: Massive power loss, strong whistling or grinding, heavy oil consumption, blue smoke when accelerating
Like the CEUA, the DDTA also shows camshaft scuffing. The camshafts matched to the cylinder heads cannot be freely exchanged, making repairs complex.
Symptoms: Tapping noises from the valvetrain, rough running at low rpm, power loss
The 4.0 TFSI V8 high-pressure pump can generate metal swarf in the oil from cam wear. Improved tappet rods were introduced from 2017. Short oil change intervals are essential on the EA825.
Symptoms: Starting problems, power loss especially at low fuel pressure, metallic clattering, engine warning light
D5 S8 owners with 4.0 TFSI report EPC warning lights (Electronic Power Control) that illuminate on start-up, pointing to faults in the engine management or throttle body control.
Symptoms: EPC warning light on start-up, occasional illumination while driving, increased fuel consumption
Vehicle Weaknesses 6
A contact fault in the seat heating cable can cause the passenger occupant detection system (PODS) to detect a malfunction and deactivate the passenger airbag. Affects A8 model years 2017–2020. Free repair at dealer.
High-voltage battery cell modules can overheat during charging, in extreme cases causing a vehicle fire. KBA action 93QQ, production period 08/2019–07/2024. Solution: software update with improved temperature monitoring and charge current limiting.
The adaptive air suspension on the A8 D5 shows weaknesses from 100,000–150,000 km: rear air bellows become porous, the compressor overheats from continuous running when bellows leak. Cold temperatures worsen the sealing of the rubber membranes.
The 48-volt electrical system of the A8 D5 can produce charging faults on the lithium-ion buffer battery. When it fails, numerous warnings appear on the instrument cluster (assistance systems unavailable, steering, engine shutdown warning). Replacement is expensive.
The rubberised soft-touch surfaces on light switches, trim panels and door inner handles peel off on virtually all vehicles with age. A sticky, greasy surface develops especially on frequently touched areas.
The digital instrument cluster (Virtual Cockpit) occasionally freezes and the navigation map stops updating. 2021 models were recalled due to a hardware fault in the connection cable (software solution). Older models are mostly resolved through software updates.
Reports & Tests
7 owner complaints filed with NHTSA (2017–2024). Most reported: Electrical (3), Powertrain (3), Engine (2).