Audi S4 Problems: 6 Issues Every Owner Should Know
2000-2025 model years · 448+ owner reports · Updated April 2026
According to Au7o's analysis of 448+ owner reports, the 2000-2025 Audi S4 has 6 documented known issues, with 4 rated critical. The most serious are 3.0T Supercharger Nose Bearing Failure ($600-$2,500 repair), B6/B7 4.2L V8 Timing Chain Tensioner Failure ($4,000-$8,000 repair), B5 2.7T Turbocharger Failure ($2,000-$5,000 repair) and B5 S4 2.7T Timing Chain Guide Failure ($3,000-$6,000 repair). The most commonly reported issue is 3.0T Intake Valve Carbon Buildup with 184 owner reports. Across all issues, repair costs range from $300 to $8,000. DIY maintenance guides at au7o.io.