The 2009 Audi S4 is a compact luxury sport sedan (and available as an Avant wagon) that blends everyday comfort with serious all-weather performance. It’s ideal for drivers who want a refined interior, confident Quattro traction, and a factory-tuned V8 soundtrack without moving up to a larger, heavier performance car. This model year sits at the end of the B7-generation S4 run in the U.S., making it one of the last S4s powered by Audi’s 4.2L naturally aspirated V8 before the next generation moved to supercharged V6 power. In the market, it competes with cars like the BMW 335i and Mercedes-Benz C-Class performance variants, leaning more toward grip, build quality, and a premium cabin feel.

- 4.2L V8 performance: The 2009 S4 uses a 4.2-liter naturally aspirated V8 (commonly rated around 340 hp) with strong midrange pull and a distinctive exhaust note that many owners consider a highlight. - Quattro all-wheel drive: Audi’s Quattro system delivers excellent traction in rain and snow and helps put V8 power down more confidently than many rear-wheel-drive rivals. - Transmission choices: Many 2009 S4s came with a 6-speed manual, and some markets offered an automatic option. Manual cars are often sought after for driver engagement and long-term enthusiast value. - Sport-tuned chassis and braking: Firmer suspension tuning, supportive sport seats, and strong brakes give the S4 a more focused feel than the standard A4 while still staying comfortable for commuting. - Premium interior and tech: Typical equipment includes high-quality materials, available navigation, and upscale details that still feel modern for its age when well cared for.

Shoppers researching “2009 Audi S4 problems,” “2009 Audi S4 reliability,” and “2009 Audi S4 common issues” should know this is a rewarding car, but ownership can get expensive if prior maintenance was skipped. Here are common concerns reported by owners: - Timing chain system wear (higher mileage): The 4.2L V8 uses a timing chain setup at the rear of the engine. As mileage climbs (often 100,000+ miles), some cars develop chain rattle at startup, tensioner wear, or guide issues. Repairs can be labor-intensive due to engine access and are a major item to verify before buying. - Oil consumption and valve cover gasket leaks: Higher-mileage 4.2L engines can consume oil, and leaks from valve cover gaskets or other seals may appear with age. Watch for burning oil smells, spots under the car, and low oil warnings between services. - Coil packs and ignition-related misfires: Misfires under load or rough idle can be caused by aging coil packs and spark plugs, commonly showing up anywhere from 60,000 to 120,000 miles depending on heat cycles and service history. - Cooling system wear: Thermostats, coolant crossover components, and aging hoses can create leaks or overheating concerns as the car ages. A sweet coolant smell, fluctuating temps, or repeated top-offs are red flags.