Audi S6
Audi 3.0 TDI V6 with 344 PS (253 kW) in the S6 C8 and S7 C8. Mild hybrid system with 48V belt starter-generator. Electric compressor for instant boost pressure. Very powerful diesel sports engine with low consumption around 7L/100km.
S6 TDI — diesel instead of V8 for Europe, the surrender
In Europe, the S6 C8 came as TDI only — no V8 TFSI. 349 hp diesel with electric supercharger, impressive on paper, emotionally a surrender. Anyone wanting the TFSI had to move to the US or buy an S8.
Engine Weaknesses 5
In the 3.0 TDI EA897 camshafts fracture due to material defects — affecting all four camshafts of the V6. A fracture inevitably causes engine damage. Audi acknowledged the issue via TPI 2043172.
Symptoms: Ticking or knocking engine noises beyond normal diesel sounds, then power loss and engine failure
The 3.0 TDI is prone to timing chain elongation and tensioner wear. A chain jump causes pistons and valves to collide, causing total engine damage. Replacement requires 15–20 labour hours.
Symptoms: Rattling or knocking on cold start and under load, engine stumbling, warning light
Diesel-typical soot formation on the 3.0 TDI injectors leads to injection problems and increased wear. Fuel additives and premium diesel can delay the need for cleaning.
Symptoms: Rough idle, increased consumption, hesitation under load, power loss at higher rpm
The 3.0 TDI dual-mass flywheel wears faster under high torque, especially with frequent city driving and low-rpm operation. Replacement is cost-intensive.
Symptoms: Dull clunking noises on take-off and gear changes, vibrations at idle, rough running when lifting off the throttle
The 3.0 TDI diesel particulate filter clogs with frequent short-trip use as the regeneration temperature is not reached. After software updates the DPF loading was sometimes increased.
Symptoms: Power loss, increased consumption, limp mode, DPF warning light, increased oil dilution smell
Vehicle Weaknesses 5
On vehicles from model year 2018 the panoramic roof can detach due to adhesive bond failure. Audi issued a recall; confirm completion before purchase.
The 48V belt-driven starter-generator (BSG) is a known weak point of the C8. When it fails the entire 48V electrical system goes offline. Audi granted an extended warranty of 7 years on the component.
On some C8 models moisture enters through a leaking wheel arch and causes a musty smell inside the vehicle as well as possible corrosion on electrical components.
On the S6 C8 the adaptive cruise control (ACC) and MMI infotainment system drop out sporadically. The automatic emergency brake triggers too early. Primarily affects 2018–2021 models.
The S6 C8 with 450 hp and a 2,000 kg kerb weight places heavy demands on the braking system. Spirited use leads to frequent brake disc replacement, especially on the front axle.