NHTSA Complaint #11711951 — 2021 CHEVROLET SILVERADO 1500

Component that failed: The valve train system failed due to collapsed lifters in the GM 5.3L L84 engine. The lifter failure caused internal camshaft damage requiring major repair. The failed components were removed by the Chevrolet dealership and should be available through the repair facility if inspection is requested. Safety risk: The engine failure caused a sudden and severe loss of power while driving. The vehicle would not accelerate beyond approximately 45 mph on a 65 mph roadway while en route to the dealership, creating an unsafe speed differential. When attempting to accelerate to pass another vehicle on a two lane road, the engine backfired and immediately throttled back, making it unsafe to complete the pass. The check engine light illuminated at the exact moment the vehicle lost power during the passing attempt. This sudden propulsion loss during an active maneuver created a hazardous driving condition. Dealer confirmation: An authorized Chevrolet dealership diagnosed collapsed lifters which damaged the camshaft and confirmed this as a known failure pattern in GM L84 engines. Inspection by others: Vehicle was inspected and repaired by the dealership. No accident occurred, so no police or insurance inspection was involved. Warnings or symptoms: No prior warning lights appeared before the passing event. The check engine light came on during the failure while accelerating. Additional context: This failure aligns with widely documented lifter collapse defects in GM 5.3L L84 truck engines. The breakdown was not caused by maintenance or wear and tear but by premature internal component failure known across this engine platform.