NHTSA Complaint #11695909 — 2021 GMC SIERRA 1500

On [XXX], at approximately 15,873 miles and while on the freeway approximately 30 miles from my home, my GMC Sierra 1500 with the L84 engine experienced a failure of the DFM lifter assembly. This required a significant engine disassembly and the replacement of multiple valvetrain components. This repair was performed at Gold Rush Chevrolet in Auburn, CA, as documented in the enclosed service invoice. GM has issued Technical Service Bulletins and product communications addressing similar lifter failures in Gen V small-block V8 engines with DFM/AFM, including Service Update N212353840, PIP5776, #19-NA-219, and related updates. Industry coverage and owner reports and current Class Action Lawsuits indicate that these failures can recur, even after initial repairs, due to the high cycling frequency of the DFM lifters. Given the nature of the defect and GM’s documented acknowledgement of the issue, I am requesting that GM extend the powertrain warranty coverage for the engine and related valvetrain components for a period of 10 years,100,000 miles as a goodwill policy adjustment. A warranty extension would ensure customer confidence and protect against the significant cost of a repeat failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)