The Sonata is spacious and well-equipped value, but the Theta II engine family's failure risk is the single most important check.
Compiled & reviewed by the VehicleFaults Research Team · last reviewed July 2026
The most commonly reported faults on the 2015–2019 Hyundai Sonata are Theta II 2.0T/2.4L engine failure (bearing/knock) — subject to recalls and warranty extensions, Excessive oil consumption and Electric power steering faults. Of the documented issues, 1 rated critical and 1 rated high · these are the ones worth inspecting first. Full inspection points, onset mileage and what to check are listed below.
Based on the documented faults on this page for the Hyundai Sonata.
Guidance only · reflects reported patterns, not a specific car's condition.
Which faults an average example has usually reached depends on its age. Pick a model year for the faults that matter on that build.
Theta II 2.0T/2.4L engine failure (bearing/knock) — subject to recalls and warranty extensions.
Excessive oil consumption.
Infotainment and sensor glitches.
Electric power steering faults.
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Check this exact carYes — the Theta II engines have a well-documented failure history with recalls; verify the knock-sensor update and any engine replacement.
It offers strong value, but only with confirmed recall completion and clean oil-consumption history.
Hyundai added a knock-sensor detection system to catch bearing wear early — confirm it was installed.
Faults are compiled from documented recalls, technical bulletins, owner reports and mechanic sources, then reviewed for accuracy. This is guidance only · not a substitute for a professional inspection.