Audi A4
Most powerful V6 diesel in the B9 with up to 210 kW. Engine from the SQ5 family. Very strong pulling power; exclusively with all-wheel drive and automatic.
Sporting character — driving fun guaranteed
272 hp 3.0L with noticeable temperament.
Engine Weaknesses 5
On the pre-facelift 3.0 TDI, a material defect can cause camshaft fracture. CSWB is reportedly less affected than CRT according to the TPI, however knocking noises are also reported on CSWB units. Complete engine replacement €15,000–20,000.
Symptoms: Ticking or knocking engine noises clearly louder than normal diesel working noise, audible with engine running and bonnet open
All 3.0 TDI V6 variants can develop chain problems, especially with long oil change intervals. The CSWB is considered less affected than CRT/CZV, but not immune. Replacement costs €3,000 and above.
Symptoms: Rattling on cold start that improves after warm-up, camshaft position fault codes, slight power loss
From approximately 120,000 km the 3.0 TDI injectors can soot up or fail. Audi prices around €4,000; budget alternatives around €1,400 in parts plus €400 fitting and coding.
Symptoms: Heavy white smoke while driving, engine vibrations, rough idle, increased fuel consumption
The V6 TDI is thermally highly stressed despite moderate power output. Turbo bearing wear typically appears from 200,000 km but can occur much earlier with oil starvation or overheating.
Symptoms: Power loss, blue or black smoke, audible turbo shaft play, oil in intake tract
Short-trip use prevents DPF self-regeneration. When overloaded a replacement costing €2,000 or a removal and burn-out cycle is needed. Regular motorway driving is essential.
Symptoms: DPF warning light on dashboard, power reduction in limp mode, increased fuel consumption, frequent regeneration cycles
Vehicle Weaknesses 7
Defective coolant valves cause coolant loss that can silently lead to overheating. Temperature sensors and thermostat housing are a weak point from 60,000–100,000 km.
The rubber bushings in the upper control arms wear prematurely, in some cases from as early as 60,000–80,000 km. The issue is said to have been fixed only with the 2019 facelift.
Certain 19-inch tyre combinations on the B9 lead to premature wear on the inner flanks. The cause is a suspension setup not optimally tuned for larger wheels. Regular wheel alignment recommended.
The S tronic dual-clutch gearbox judders when pulling away and at low speeds. The mechatronics unit can become defective.
Water pump and thermostat housing typically fail between 60,000 and 170,000 km. A well-known weak point on the 2.0 TFSI and 2.0 TDI.
The S tronic dual-clutch gearbox exhibits a known juddering in D and R at idle that Audi classes as within the state of the art. Diesel variants may additionally creep.
The MMI infotainment system frequently exhibits Bluetooth connectivity problems in facelift models: choppy music playback, missed ringtones. Software updates do not always provide a permanent fix.