Audi A4
High-revving V6 petrol with direct injection and 188 kW. Timing chain on the gearbox side, very labour-intensive to replace. Distinctive sound.
V6 naturally aspirated with love of revs
256 hp V6 — loves to rev, sounds good doing it.
Engine Weaknesses 6
The Nikasil coating on the cylinder bores detaches, leading to piston slap, heavy oil consumption and power loss. Engine damage is inevitable; repair is often uneconomical.
Symptoms: Heavy oil consumption, knocking from the engine, power drop, engine failure in extreme cases
The 3.2 FSI AUK is known for piston slap — pistons or cylinder bores wear and produce knocking noises with increased oil consumption. Repair is rarely economical given the costs involved.
Symptoms: Knocking from the engine, increased oil consumption, sudden power loss, loud slapping under load
The timing chain on the 3.2 FSI can stretch and cause engine damage if it jumps. More common than on the 3.0 TDI. Rattling on cold start is the first warning sign.
Symptoms: Cold-start rattle, power loss, rough running, engine damage in the worst case
Direct injection without intake port wetting leads to carbon deposits on intake valves and in the combustion chamber. Coking causes rough running, poor cold-start behaviour and increased fuel consumption.
Symptoms: Judder on cold start, rough idle, increased fuel consumption, power loss
The AUK has four hydraulic camshaft adjusters. Faulty adjusters or their solenoid valves cause misfires, engine warning light and cold-start rattle. Replacement including timing chain often over 1,500 €.
Symptoms: Cold-start rattle, engine warning light, combustion misfires, fault code for camshaft phasing
The V6 with six cylinders is prone to individual ignition coil failures and worn spark plugs. Symptoms are misfires on individual cylinders stored as fault codes.
Symptoms: Judder under load, combustion misfires on specific cylinders, engine warning light flashing
Vehicle Weaknesses 7
The CVT Multitronic gearbox tends to judder when pulling away, rpm fluctuations and complete failure when not serviced properly. Control unit defects often appear from around 100,000 km.
On the 2.0 TDI the hexagonal shaft of the oil pump drive can snap, causing immediate oil pressure loss and engine damage. Preventive replacement is recommended.
Airbags manufactured by Takata can deploy with excess pressure and propel metal fragments. Worldwide recall campaign.
Control arms and tie rod ends wear prematurely. Clunking and rumbling on poor surfaces. The multi-link front axle is maintenance-intensive.
Defective ignition coils can immobilise the engine or cause severe running roughness. Mainly affects 1.8T and 2.0 TFSI engines.
From model year 2004 Audi used partial bonding instead of full galvanisation. Wheel arches and sills are vulnerable to rust, especially on older examples without cavity protection.
Rear wheel bearings fail regularly on the A4 B7. Quattro models show increased wear.