Mercedes-Benz C300 engine failure problems

Filed Sep 21, 2026 · Engine, Transmission · CA

The M264 2.0L engine suffered a catastrophic internal failure. While making a left turn at an intersection, the vehicle suddenly shut off and stalled, leaving the car stranded in active traffic and creating an immediate safety risk. Prior to the shutdown, the check engine light came on accompanied by severe shaking and misfires. The vehicle was inspected by an authorized dealership service center, which confirmed complete engine failure. Mercedes-Benz issued a 15-year/150,000-mile extended warranty for the M264 exhaust valve and cylinder head assembly, but warranty coverage was refused because the cylinder defect progressed to total engine destruction. The vehicle remains available for inspection upon request.

Filed Aug 7, 2026 · Engine · 88,000 miles · WI

The contact owns a 2021 Mercedes-Benz C 300. The contact stated that while depressing the accelerator pedal, there was a loud knocking sound coming from the engine compartment while accelerating. There were no warning lights illuminated. The vehicle was taken to the dealer to be diagnosed, and it was determined that the spawn rod was fractured, causing engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The contact stated that the engine was previously repaired because of the head gasket failure in 2024. The manufacturer was informed of the issue, and a case was opened. The failure mileage was approximately 88,000.

Filed Jul 19, 2026 · Engine · FL

Driving a 2024 mercedes c300 on the florida turnpike in the left lane at 70 MPH the engine suddenly slowed down. While the vehicle slowed in heavy traffic I was able to merge to the outside lane where it stopped. I called mercedes emergency who suggested waiting a while and try starting the vehicle . After a few minutes I was able to start the vehicle and drive it to the dealer. The dealers computer acknowledged the stoppage and after three weeks and 500 miles driven by the dealer was not able to determine the cause and plans to replace the engine computer. I am [xxx] old and afraid to drive this car and want to end the lease. Information redacted pursuant to the freedom of information act (foia), 5 u.s.c. 552(b)(6)

Filed May 22, 2026 · Engine · CO

the federal safety agency Safety Complaint – 2016 Mercedes-Benz C300 Vehicle: 2016 Mercedes-Benz C300 | Mileage: 74,662 miles What Happened I’m filing this complaint because my 2016 Mercedes-Benz C300 suffered a sudden, complete engine failure at 74,662 miles, and I believe it’s a safety risk that deserves investigation. I’ve owned this car since 2016 and followed every recommended service interval. All available warranties were purchased and maintained. The car showed absolutely no signs of trouble before this happened. Last week before filing, I was driving normally when the check engine light came on without any prior warning — no oil pressure light, no temperature alert, nothing else. Within minutes, the engine shut off completely. The car rolled to a stop and I noticed oil leaking from the front of the engine. It was towed to an authorized Mercedes-Benz dealership, where they confirmed the engine suffered a catastrophic internal failure and needs to be fully replaced. Why This Is a Safety Concern No advance warning. The check engine light appeared only minutes before the engine died. That’s not enough time to safely exit a highway or busy road. A sudden total engine failure at speed affects steering, braking assist, and reaction time — it could easily cause a serious accident. Engine failure at 74,662 miles is not normal. A complete engine failure on a well-maintained luxury vehicle at under 75,000 miles strongly suggests a manufacturing defect or design flaw, possibly affecting other vehicles of the same model year. Oil leak at engine front. The leak observed at failure likely points to a specific component or seal failure. If this is a design weakness, other 2016 C300 owners may be at risk without knowing it. What I’m Requesting 1.Open an investigation into the 2016 Mercedes-Benz C300 for sudden engine failure and inadequate warning systems. 2.Determine whether other owners have reported similar incidents. 3.Evaluate whether a safety recall is warranted.

Filed Apr 23, 2026 · Electrical, Engine · NY

Vehicle has ongoing and recurring electrical and engine-related defects that affect safe operation. The primary systems involved are the electrical system, engine ignition system, and powertrain. The vehicle is available for inspection upon request. Prior service records show issues beginning in 2020 involving repeated electronic system failures requiring multiple repairs and component replacements. Since purchasing the vehicle in April 2023, the vehicle has developed more serious failures, including: – September 2024: Check engine light with loss of power and inability to exceed safe driving speeds – October 2024: Engine misfiring due to ignition coil failure requiring replacement of ignition components – September 2025: Additional ignition coil electrical fault (code P0353) The problem has been reproduced and confirmed through dealership service inspections and diagnostic reports. Warning indicators, including the check engine light, appeared prior to failure events. These defects create a safety risk due to potential loss of power, engine failure, and unreliable vehicle operation while driving, which could increase the risk of an accident. The issues have required multiple repairs without permanent resolution and appear to be ongoing and worsening over time.

Filed Feb 17, 2026 · Engine · GA

I am reporting a catastrophic repeat engine failure on my 2020 Mercedes-Benz C300. On October 9, 2025, with 26,589 miles, the vehicle suffered a Cylinder 2 failure (exhaust valves), causing a dangerous loss of power in traffic. I paid $4,100.43 for a $10,000 plus cylinder head replacement at an authorized dealer (Mercedes-Benz of Atlanta South) on November 13, 2025. Following the repair, the vehicle continued to exhibit multiple 'Check Engine Oil Level' warnings. On February 4, 2026—less than 90 days after the major repair—the engine suffered a total catastrophic failure. The dealer now states the entire engine requires replacement. This repeat failure of a critical engine component at low mileage poses an unreasonable risk of stalling or sudden loss of propulsion on high-speed roads. I am aware of the January 2026 Mercedes-Benz warranty extension (NCU 30-P-072328) for this specific M264 engine defect, which confirms a known manufacturing flaw that the current dealership repair process failed to remediate, leaving me in an unsafe vehicle.

Filed Dec 29, 2025 · Steering · 98,000 miles · CA

The contact owns a 2010 Mercedes-Benz C300. The contact stated that the vehicle had failed to start after several attempts; however, the infotainment system was turned on. The contact stated that the engine failed to start. No warning lights were illuminated. The contact related the failure to an unknown steering coupling interlock mechanism recall. The vehicle was not taken to the dealer or to an independent mechanic. The vehicle was not repaired and remained at the residence. The manufacturer was not made aware of the failure. The approximate failure mileage was 98,000.

Filed Dec 22, 2025 · Engine, Fuel system · FL

This vehicle was brought to an authorized Mercedes-Benz dealership for regularly scheduled maintenance. Shortly after this service, the vehicle began experiencing significant issues including difficulty accelerating, engine hesitation while driving, and noticeable shaking at idle. This car has never overheated. The vehicle was returned to the dealership for inspection. The dealership diagnosed a cracked cylinder head and advised that the repair requires replacement of the cylinder head at an estimated cost of approximately $11,000. The failed component is available for inspection and the vehicle is currently at the dealership. The vehicle has approximately 46,000 miles, has been regularly maintained, garaged, and driven under normal conditions. These symptoms created engine performance issues that could result in loss of power or inability to accelerate while driving, creating a potential safety risk, especially in traffic or at highway speeds. I regularly transport my young grandchild in this vehicle. The possibility of sudden engine failure, loss of power, or breakdown while driving raises significant safety concerns for myself and any passengers, particularly a young child. The failure has been confirmed by an authorized Mercedes-Benz service center. During my own research, I discovered there have been recalls involving similar engines for the same model year, as well as multiple owner complaints reporting similar engine or cylinder head failures on this vehicle. I contacted Mercedes-Benz customer care on December 17, 2025, after receiving the dealership diagnosis, and was advised that I would receive a response within 72 hours. As of today, I have not received any response. I attempted to call customer care again, but the phone system would not accept a voicemail and no representative answered. My case number with Mercedes-Benz is 19653254. No prior abuse, misuse, or abnormal driving conditions occurred. The vehicle was properly maintained.

Filed Nov 25, 2025 · Engine · CA

2021 Mercedes-Benz C300 with M254 2.0L turbo engine experienced sudden cylinder head failure at 44,000 miles due to manufacturing porosity in the cylinder head and camshaft bore scoring. Dealer confirmed defect. This is a known, recurring issue on 2021–2023 M254 engines with multiple documented failures under 50k miles. Sudden loss of compression and misfires create a safety risk of engine failure or fire while driving. TSB NUMBER LI07.16-P-074000 (February 2023, updated multiple times). This is a known production/early break-in issue with the M254 engine, not the result of owner misuse or delayed maintenance.

Filed Oct 23, 2025 · Engine · AZ

My vehicle only had 31,000 miles and I experienced engine failure. I bought a new engine for 16, 500. 00 dollars. Mercedes Benz did nothing. I almost got in to several accidents because the engine completely stop on the interstate. Almost got hit by several cars. This is unacceptable.