Audi RS5
The 2.9 TFSI V6 BiTurbo was developed in collaboration with Porsche — related to the engine in the Boxster/Cayman GTS and Macan Turbo. Twin-scroll turbos in the Hot-V, 450 PS and 600 Nm from 1,750 rpm. Central wear issue: rocker arm bearings in the cylinder head. Early batches (before GP1 production code, approximately up to mid-2019) had rocker arms with too-small bearing rollers — risk of fracture, rollers falling into the sump. Improved from GP1 onwards. When buying a B9 RS4/RS5 built before mid-2019: check the production code. Preventive retrofit is possible — part costs £16, but engine removal required.
RS5 Coupé — same BiTurbo V6, better proportions
Same 450 hp twin-turbo as the RS4 B9, but more cohesive in a coupé. The lower roofline suits the GT character better than the wagon. Missing the B8 RS5 V8 sound? Yes. Still a seriously fast GT coupé? Also yes.
Engine Weaknesses 5
In the 2.9 TFSI BiTurbo (DECA), rocker arm bearing rollers can fall out of the cylinder head and end up in the oil pan. Early production years (up to approx. 2019) are especially affected. A revised design with thicker bearing rollers was introduced. No official recall, but serious consequences are possible.
Symptoms: Knocking or rattling noises from the cylinder head, metal particles in the engine oil, sudden power loss, engine fault codes
As a pure direct injector without port injection, the EA888 DECA builds pronounced soot deposits on the intake valves. Crankcase ventilation oil mist and EGR gases thermally bond to the valve heads. Cleaning from 40,000–60,000 km onwards is recommended.
Symptoms: Creeping power loss, stumbling under partial load, rougher idle, increased fuel consumption especially in city traffic
The 2.9 TFSI DECA shows elevated oil consumption with spirited driving due to high thermal loads and boost pressures. Coked piston rings worsen the problem. Regular oil level checks between service intervals are essential on the RS4/RS5 B9.
Symptoms: Dropping oil level between oil changes, occasional blue smoke under hard acceleration, light oil smell
Both turbochargers of the 2.9 TFSI DECA can lose shaft seals at high mileage or with aggressive use. Oil consumption rises, oil mist enters the intake. Since both turbos are on the inner engine side, removal is very labour-intensive.
Symptoms: Increasing oil consumption, light blue smoke, oil traces in the intercooler, whistling under load
The 2.9 TFSI DECA uses a timing chain system where tensioners wear and can cause rattling on cold start. High power output and spirited use increase the load on the timing drive. Early tensioner replacement prevents chain elongation.
Symptoms: Rattling on cold start that subsides at operating temperature, camshaft fault code, MIL with timing chain fault
Vehicle Weaknesses 7
Around 1.16 million vehicles with 2.0 TFSI (model years 2012–2017) were recalled. The electric auxiliary water pump can overheat, cause a short circuit and in extreme cases start a fire.
The S tronic dual-clutch gearbox tends to shudder and judder at low speeds. Clutch disc wear in city traffic is severe. A full rebuild is often necessary.
Early starter battery weakness and associated infotainment faults. MMI shows frozen screens or crashes when the on-board voltage drops.
On some A5 F5 Sportback and Coupe models water enters the boot. The cause is an inadequate seal in the area of the tailgate aperture.
Some A5 F5 models show steering wheel vibrations between 80 and 120 km/h. Audi addresses this as a goodwill gesture by replacing the control arms with hydraulic mounts.
Starter battery fails on early F5 models, particularly with short-trip use. Cold-start problems in winter are frequent.
Well-known fault code with the automatic headlight level adjustment. The issue occurs across all build years and has never been fully resolved by software update.
Reports & Tests
102 owner complaints filed with NHTSA (2016–2023). Most reported: Electrical (48), Other (29), Backup Camera/Sensors (17).