2022 Mercedes-Benz CLA 250 4MATIC Problems

The check engine light illuminated and the engine began running rough with misfires. Stored fault codes included P0301 and P0302 (cylinder 1 and cylinder 2 misfire detected) and P0315. An initial repair facility replaced spark plugs, ignition coils, the main battery and the auxiliary battery, which did not resolve the condition, and the vehicle was referred to an authorized Mercedes-Benz dealer. The Mercedes-Benz dealer performed an engine inspection and found compression of approximately 80 PSI caused by severely leaking intake and exhaust valves. The dealer determined the complete cylinder head requires replacement and estimated the repair at $7,545.72. The vehicle is currently not drivable and is available for inspection. This failure matches the condition described in Mercedes-Benz technical service bulletin LI01.30-P-072328, which identifies a leaking valve seat in the cylinder head on M260 and M264 engines and states the complete cylinder head must be replaced because valve seats cannot be reworked. Mercedes-Benz USA has issued an emission extended warranty covering the exhaust valve system on these vehicles, describing wear of the valve guide and seat ring due to increased lateral forces during operation, causing misfires on cylinders 1 through 4 and illumination of the check engine light. The vehicle is within the stated 15 year / 150,000 mile coverage limit, but the warranty claim was denied on the basis of maintenance history. The vehicle was serviced continuously, including three Mercedes-Benz dealership services, with oil and filter changes at intervals of roughly 13,000 miles and no gaps. The safety concern is loss of engine power and misfiring during operation. The condition caused the engine to run rough, surge, and stall while driving, including in traffic.