Hyundai Sonata Common Problems and Years to Avoid

Each row links to the full specification for that generation, including trim-by-trim breakdowns and the part numbers. Where engines within a generation differ, that page separates them.

The problems and recalls on a Hyundai Sonata is set by its generation, not its model year, so each generation has one page carrying the complete figures, part numbers and fitment notes for every year it covers.

What are the most common problems with the Hyundai Sonata?

The recurring ones are: 2.5l smartstream (g4kn) oil dilution and oil consumption; n line oil-cap vs. owner's-manual viscosity confusion. Each is detailed above with symptoms, affected years, and typical cost.

How much do Hyundai Sonata repairs typically cost?

Typical figures for the issues above: 2.5l smartstream (g4kn) oil dilution and oil consumption, $0 (monitoring/top-offs) to $4,000+ for engine work if wear becomes severe; n line oil-cap vs. owner's-manual viscosity confusion, N/A, verify viscosity against the owner's manual, not the cap, before an oil change.