NHTSA Complaint #11667844 — 2009 GMC SIERRA 1500

To Whom It May Concern, I am submitting this report regarding repeated engine and valve lifter failures in my 2009 GMC Sierra 1500 with a 5.3L V8 engine, VIN: [XXX] . 1. Component/System Malfunctioned: Both the original engine and a replacement engine—professionally installed by a Chevrolet dealership—experienced valve lifter failure related to the Active Fuel Management (AFM) system. The most recent failure was sudden and unexpected. The engine may be available for inspection upon request. 2. Safety Risk: Engine failure puts driver and passenger safety at serious risk, particularly if the vehicle loses power unexpectedly while in motion. In both instances, the failure created unsafe driving conditions. 3. Reproduction/Confirmation: The issue was confirmed by a Chevrolet dealership during the initial engine failure and again more recently on the current engine, which is now exhibiting the same failure. 4. Inspection Status: The vehicle has been inspected by the same dealership that performed the original engine replacement. To my knowledge, it has not been inspected by GM corporate, police, or insurance representatives. 5. Warning Signs: There were no warning lamps, messages, or clear symptoms prior to the failure. The problem occurred without advance notice and did not provide an opportunity to address it before damage occurred. This is the second engine failure my truck has suffered from the same issue, even after dealership installation of a new motor. I urge the NHTSA to investigate whether this represents a broader defect in GM 5.3L AFM-equipped engines. It is unacceptable that repeated critical failures can occur in these engines with no warning and no resolution, even after following proper replacement procedures. Thank you for your attention. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)