The 2004 Audi S4 is a compact executive performance sedan (also available as an Avant wagon) that blends everyday practicality with serious V8 power and standard all-wheel drive. This model sits in the B6-generation S4 lineup (2004–2005 in the U.S.), positioned as a high-performance step above the A4 and a more understated alternative to many rear-wheel-drive sport sedans of its era. It’s ideal for drivers who want a refined interior, confident all-weather traction, and a muscular, naturally aspirated engine note. In today’s market, it’s often sought as a value-performance used car, but buyers should budget for above-average maintenance.

1) 4.2L V8 performance: The 2004 S4 uses a naturally aspirated 4.2-liter V8 (factory-rated around 340 hp) known for strong midrange torque and a distinctive sound. 2) Quattro all-wheel drive: Audi’s Quattro system is standard, delivering excellent traction in rain or snow and confident handling when paired with quality tires. 3) Transmission choices: Offered with a 6-speed manual or a 6-speed automatic (Tiptronic), letting buyers choose between a more engaging drive or easier commuting. 4) Sport-tuned chassis and brakes: Firmer suspension tuning than the A4, stronger braking hardware, and a planted feel at speed make it a capable back-road and highway car. 5) Premium cabin and equipment: Supportive sport seats, upscale materials, available leather and navigation, and the solid, quiet B6 build quality are key reasons enthusiasts still seek this model.

Shoppers researching 2004 Audi S4 problems, 2004 Audi S4 reliability, or 2004 Audi S4 common issues should know this is a rewarding car when maintained, but it can become expensive if neglected. 1) Timing chain guide and tensioner wear: The 4.2L V8 uses a timing chain setup located at the rear of the engine. Rattling at cold start, chain noise, or fault codes can indicate guide/tensioner wear. This can appear anywhere from roughly 80,000–140,000 miles depending on service history and driving habits, and repairs are labor-intensive. 2) Coil packs and ignition misfires: Misfires under load, rough idle, or flashing check engine lights are often tied to aging coil packs and spark plugs, sometimes showing up around 60,000–100,000 miles. This is typically manageable, but it’s important to diagnose promptly to protect catalytic converters. 3) Oil leaks and consumption: Valve cover gaskets, cam seals, and other aging seals can leak as mileage climbs (commonly after 90,000 miles). Some owners also report oil consumption; staying on top of oil level is essential for engine longevity. 4) Cooling system and auxiliary components: Plastic cooling system parts and aging hoses can become brittle over time. Thermostat or coolant leaks may appear with age, and accessory items like the serpentine belt system and tensioners should be inspected as preventive maintenance.