2016 MERCEDES-BENZ Amg C63S

2016 Mercedes-Benz C63 S AMG, M177 4.0L twin-turbo V8. This engine is marketed under Mercedes-Benz's "One Man, One Engine" philosophy — hand-assembled by a single master technician. It failed irreparably at 67,323 miles on a properly maintained vehicle owned by a 14-year Mercedes-Benz customer who has purchased six Mercedes-Benz vehicles. All maintenance performed on schedule with genuine OEM Mercedes-Benz parts at Mercedes-certified shops. At approximately 65,000 miles, check engine light illuminated with cylinder 7 misfire. A Mercedes-certified shop found and replaced a burnt spark plug and all 4 ignition coils with OEM parts. Misfire cleared. Three months later at 67,000 miles, shaking and check engine light returned. All 8 spark plugs replaced with OEM parts. Misfires returned within 100 miles — now on cylinders 1, 3, and 7 — accompanied by violent engine shaking and a fuel smell. Vehicle brought to authorized Mercedes-Benz dealer. Full diagnostic performed including borescope inspection. Confirmed: broken spark plug ceramic and unrepairable piston pitting in cylinder 4 and engine damage. Dealer confirmed engine is not repairable and recommends complete engine replacement. All findings documented on dealer repair order. Vehicle remains at the dealer and is available for inspection. Mercedes-Benz has published at least three Technical Service Bulletins on persistent misfires specific to this engine: LI54.21-P-062006 (multiple revisions — ECU ground faults, borescope protocol anticipating internal damage), LI07.61-P-073583 (post-turbo exhaust clamp failures), LI07.61-P-069688 (intake manifold cracks). Mercedes has acknowledged this defect pattern internally and has not issued a recall. Sudden power loss and violent shaking at highway speed is a direct safety hazard. NHTSA investigation warranted.