The vehicle was being used in a normal daily driving routine. I was stopped(fortunately) at a traffic light. The light turned green and I went to proceed and began to press the gas pedal and the engine made a loud pop noise and began to barely stay running. I brought the vehicle to the shop(GM dealership) for diagnosis and repair. The motor had to be rebuilt new camshaft, lifters, etc. The vehicle is also having transmission issues, heavy vibration, hard shifts and constant fluctuations in the rpms while maintaining a set speed. The transmission issue still has not been resolved.