I am reporting a serious engine failure in my 2023 GMC Yukon XL (5.3L Ecotec3 V8) at approximately 68,775 miles. The engine began to run rough with a loud chatter noise, and both the check engine light and traction control light activated. Diagnostic tests at the dealer (F.C. Kerbeck GMC) confirmed a P0300 random misfire code and revealed that the lifter on cylinder #5 had collapsed, causing damage to the camshaft lobe. The repair required removing the cylinder head and replacing the lifter, camshaft, pushrods, valves, and associated gaskets and seals. Although I was told this was covered as a a€˜goodwill repaira by GM, I was still charged $3,450 for miscellaneous charges. I find this highly concerning and question whether these charges are consistent with GMas stated goodwill or warranty policies. In my opinion, a known lifter design flaw requiring such an extensive repair should not result in out-of-pocket costs for the vehicle owner. This failure resulted in a severe misfire and significant performance issues that I believe raise serious safety concerns, including the potential for sudden loss of power while driving. I am submitting this report to NHTSA to ensure this issue is documented and to request that it be included in any broader investigation into GM lifter system failures. Repair invoices are available upon request