The contact owns a 2014 Hyundai Sonata. While driving at various speeds, the steering wheel was shaking and jumping, with the headlights flickering, and the steering wheel lost resistance, and became easier to maneuver. While turning the vehicle either to the left or the right, there was a vibrating sound coming from underneath the hood of the vehicle. After the sound occurred, the contact noticed that after turning off the vehicle and then attempting to restart the vehicle, the vehicle failed to start. The contact manually moved the serpentine belt first to successfully start the vehicle. The exterior lights failed to illuminate intermittently. The air bag and battery failure warning lights were illuminated. The vehicle was included in NHTSA Campaign Number: 17V226000 (Engine and Engine Cooling); and the vehicle was taken to the dealer and the engine was replaced. After having the recall repair completed, the failure reoccurred. The vehicle was returned to the dealer, who then diagnosed the battery was malfunctioning due to a loosened terminal. The terminal was tightened up however, the failure persisted. The vehicle was taken to a certified mechanic who tightened the terminal; however, the failure persisted. The vehicle was taken to another certified mechanic who placed an aluminum piece to assist with securing the terminal. The failure reoccurred. The vehicle was not diagnosed or repaired. The manufacturer was not informed of the failure. The failure mileage was 138,000.