The contact owns a 2021 Chevrolet Silverado 1500. The contact stated while driving at various speeds, there was an abnormal metal-on-metal grinding sound coming from the engine. The contact also stated that whenever the vehicle was started, the engine was making an abnormal knocking sound. There was no warning light illuminated. The contact had not taken the vehicle to a local dealer or independent mechanic. The vehicle was not diagnosed or repaired. The contact had received notification of NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The manufacturer was informed of the failure. The failure mileage was approximately 47,000.