The official notice
Defect
On certain vehicles equipped with a 2.0 L Nu GDI engine, the connecting rod bearings can become damaged. If this happens, the engine could make abnormal knocking noises and/or the oil pressure warning light may turn on. If you continue to drive the vehicle with these symptoms, the engine could fail and/or a fire could occur. An engine failure can cause a sudden loss of power with an inability to restart. Note: Only the Optima Hybrid and Plug-In Hybrid (PHEV) models are affected by this recall.
Safety Risk
A sudden loss of engine power could increase the risk of a crash. An engine failure could also create the risk of a fire.
Remedy
Kia will notify owners by mail and instruct you to take your vehicle to a dealer for an engine inspection test, to determine if there is bearing damage. If damage is found, the engine will be replaced. Dealers will also install a knock sensor detection system (KSDS) software that will prevent engine damage from potential excessive connecting rod bearing wear. Note: Kia recommends that you should always follow the correct vehicle maintenance schedule, which is printed in the Owner's Manual. If you experience unusual engine noise, reduced power, or a check engine/oil warning light, Kia advises you to immediately visit a Kia dealership to have your vehicle diagnosed.