The engine behind the Sonata and Santa Fe of the early-to-mid 2010s — one of the most serious, extensively documented reliability issues covered anywhere on this site, significant enough to prompt a multi-million-vehicle recall.
Manufacturing debris left in the crankshaft oil passages during production caused premature bearing wear on a significant number of these engines, which in the worst cases led to complete engine seizure, sometimes accompanied by fire risk. The scale of this issue — millions of vehicles recalled across Hyundai and its sibling brand Kia — makes it one of the most serious automotive engine defects of the past two decades. Any buyer considering this engine must treat recall and warranty extension history as the first and most important check, full stop.
Not a guarantee, but a pattern seen consistently across owner forums and independent-garage reporting.
Documented failures have occurred across a very wide mileage range, since the root cause is a manufacturing defect rather than purely wear-related.
An unaddressed engine with the defect can fail with little warning beyond a rod-knocking noise.
Mileage after a confirmed recall engine replacement is the only truly meaningful indicator for this specific engine.
This is absolutely non-negotiable: check the vehicle's recall history by VIN through the manufacturer's official lookup tool before considering anything else about this car, including price, mileage or condition.
If the recall applies and shows as incomplete, do not proceed with the purchase until it is resolved — this is a genuine safety issue, not a minor inconvenience.
Listen for a rod-knocking noise, particularly at idle or under load, and treat any such noise as disqualifying regardless of what the seller claims.
Model-specific pages, with notes on how it behaves in that particular car.