One problem related to engine rattling and whining sounds has been reported for the 2012 Kia Motor Optima. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Kia Motor Optima based on all problems reported for the 2012 Optima.
Driving approx. 45mph on a busy city street, vehicle suddenly began to decelerate and a rattling noise began getting louder and louder from under the hood and finally engine completely cut off and would not start again. While attempting to get over to a safe area which happened to be the turning lane, the car rolled to a complete stop. With my family in the car with me, I had to push the vehicle over to prevent from being hit due to the vehicle stalling and the back end of vehicle was still in way of on coming traffic. After being towed to a service center, I was notified that the rod bearings seized up and my only option was engine replacement. Vehicle with such low mileage should not need engine replacement.