The Audi S3 is a midsize hatchback family sedan that has been produced by Audi since 1999. The S3 was upgraded in 2006 with a new higher-performance engine, including a new more powerful turbocharger as well as an improved suspension. These upgrades made the S3 one of the highest-performance vehicles in its class. However, like most cars that have been on the market for more than a decade, the S3 does have a number of known faults that can require maintenance or repair.
Earlier models of the water pump on the S3 included a plastic impeller part in the water pump that would eventually fail over time (leading to overheating and potential thermostat damage). This water pump can be replaced with an all-metal water pump.
The bolts attaching the heat shield between the engine and the passenger compartment are prone to come loose on the S3, leading to a rattling noise. The bolts can usually be easily and inexpensively replaced.
Corrosion along the roof rail is a common problem with S3s. The epoxy sealant along weld line joining the roof to the quarter panel weathers over time, allowing water in and leading to corrosion. A respraying of sealant is covered by warranty in vehicles less than 12 years old. The lower trim of the door panel is also prone to rust and corrosion on the S3.
The rear springs on an Audi S3 are prone to corrosion, especially if you live in a damp place or near the coast. Over time the springs can even break, usually snapping off at the base. These springs are replaceable.
Brake Vacuum Hose
The vacuum pipe connecting the brake servo mechanism to the inlet manifold is manufactured from a hard plastic, which becomes brittle and cracks around the joints as the plastic ages over time from heat cycling. Simply replace the vacuum pipe.
Glovebox Door Hinges
The glovebox door hinges on the Audi S3 will eventually wear out and snap off. Repairing this requires buying and installing a new glovebox assembly.