The contact owns a 2018 Chevrolet Silverado 1500. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The contact stated that the engine sounded abnormally rough, with a knocking sound coming from the engine. In addition, several unknown warning lights were illuminated. The contact stated that the vehicle lost motive power and was pulled over to the shoulder of the roadway. The vehicle was restarted; however, the failure reoccurred. The vehicle was towed to the dealer where it was diagnosed with failed lifters. The contact was informed that the lifters needed to be replaced. The vehicle was repaired; however, the failure reoccurred. The manufacturer was not made aware of the failure. The failure mileage was approximately 60,000.