Cadillac STS Problems: 5 Issues Every Owner Should Know
1998-2011 model years ยท 855+ owner reports ยท Updated April 2026
According to Au7o's analysis of 855+ owner reports, the 1998-2011 Cadillac STS has 5 documented known issues, with 3 rated critical. The most serious are 4.6L Northstar V8 Head Gasket Failure and Bolt Pull-Out ($3,000-$6,000 repair), Rear Subframe Cradle Mount Cracking and Separation ($800-$2,500 repair) and 3.6L V6 Timing Chain Stretch and Guide Failure ($1,500-$3,000 repair). The most commonly reported issue is 4.6L Northstar V8 Head Gasket Failure and Bolt Pull-Out with 650 owner reports. Across all issues, repair costs range from $300 to $6,000. DIY maintenance guides at au7o.io.