The contact owns a 2017 Kia Optima PHEV. The contact stated that there was an abnormally loud rattling sound coming from the vehicle. The contact stated that the check engine warning light was turning on and off. The contact stated that the catalytic converter and battery were damaged. The vehicle was taken to the local dealer, who was unable to determine the cause of the failure. The vehicle was not diagnosed or repaired. The contact contacted Putnam Kia Service (2 California Dr Suite D, Burlingame, CA 94010), Hilltop Ford (3280 Auto Plaza, Richmond, CA 94806) and Oakland Kia (2500 Webster St, Oakland, CA 94612), but no assistance was provided. The vehicle was taken to an independent mechanic who determined that the rings and seals needed to be replaced. The contact was informed that the walls were scored in the engine. The mechanic determined that the engine needed to be replaced. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 87,000.