A 2018 Hyundai Sonata is now 8 years old, so an average example has covered around 108,000 miles. A late-run car · the most reliable part of the generation, but higher-mileage wear items are usually the deciding factor. Check the state safety inspection and service history alongside the documented faults below, which are sorted by whether a 2018 car has usually reached the mileage where they appear.
Compiled & reviewed by the VehicleFaults Research Team
The 2018 Hyundai Sonata is 8 years old, so an average example has covered roughly 108,000 miles. At that mileage 3 of the documented faults are already due, so check those first.
Documented onset mileage is at or below the ~108k miles an average 2018 car has covered.
Theta II 2.0T/2.4L engine failure (bearing/knock) — subject to recalls and warranty extensions.
Excessive oil consumption.
Electric power steering faults.
Age, electronics and build-related issues that are not mileage-driven.
Infotainment and sensor glitches.
Generate a tickable pre-purchase checklist for this exact year, mileage and variant · add photos and notes as you inspect.
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.