Tl* the contact owns a 2003 ford f-150. while driving 35 mph, the contact heard an abnormal sound from the engine and the check engine warning indicator illuminated. the vehicle was taken to an independent mechanic where it was diagnosed that the lifters failed and needed to be replaced. the vehicle was repaired. the mechanic even signed off for the vehicle to pass state inspection. after retrieving the vehicle, the check engine warning indicator illuminated again and the abnormal sound returned. the local dealer and manufacturer were not contacted. the failure mileage was approximately 247,000.