Audi S7
EA839 BiTurbo V6 with 331 kW for S6/S7 C8. Switch from V8 to V6 compared to the predecessor, but with 48V mild hybrid and electric compressor, performance is nearly identical.
V6 S7 — same V8-shaped hole, now in a Sportback
Same V6+48V controversy as the S6 C8, wrapped in a Sportback body. The prettier shell can't mask the V8 void. Love the silhouette but need the V8 sound: buy a used C7, not a new C8.
Engine Weaknesses 5
Small roller bearings in the rocker arms can detach and fall into the oil pan. Affects 2.9 BiTurbo engines from early production (up to approx. 2019, code GP0). Revised rocker arms (GP1) introduced from 2017.
Symptoms: Knocking noises from cylinder head, engine roughness, misfires, metal particles in the oil
The upper timing chain tensioners of the 2.9 TFSI tend to weaken. Typical rattling on cold start that disappears after warm-up. Audi revised the tensioners; goodwill repair often possible.
Symptoms: Rattling on cold start (2,000–3,000 rpm), disappears after warm-up
The DCTB 2.5 TFSI Evo (RS3 8Y, 400 hp) shows early high-pressure pump failure on some examples. Power loss and misfires are typical symptoms.
Symptoms: Power loss under high load, rough running, fault code fuel pressure control, increased fuel consumption.
Direct injection without port injection leads to carbon deposits on intake valves. Power loss and increased consumption from around 80,000 km. Walnut blasting required.
Symptoms: Power loss, rough idle, increased consumption, poor cold-start response
BiTurbo wastegate linkage rods can wear and produce metallic rattling on overrun. Known on the EA839 BiTurbo. Repair often only possible by replacing the turbocharger.
Symptoms: Metallic clattering when lifting off throttle, especially during spirited and motorway driving
Vehicle Weaknesses 5
A7 4K models 2020–2021: nuts on rear axle control arms do not meet specification. If they fracture, the rear axle can break away uncontrollably.
53,449 vehicles A6/A7/Q5 produced 2019–2024: cell modules in the 48V battery can overheat during charging and cause a fire risk.
On the optional adaptive suspension, servo actuators inside the dampers can fail due to moisture ingress. The damper must be replaced as a complete unit.
The complex MMI system crashes or displays spurious warnings. Incorrect lighting system errors and driver assistance faults are known.
The elaborate electrical system with numerous driver assistance systems puts heavy demands on the 12V battery. Early failure especially on short-run use.