What 73 owners told NHTSA about the 2019 Mercedes-benz C-class Coupe

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.

NHTSA ODI 11706568

The contact owns a 2019 Mercedes-Benz C300. The contact stated that while driving at various speeds, the vehicle suddenly lost motive power and decelerated. The accelerator pedal was depressed while attempting to accelerate. The contact stated that the fuel gauge failed to accurately display the level of fuel in the tank. The check engine warning light was intermittently illuminated. The vehicle was taken to the dealer, who diagnosed that the fuel level sensors had failed. The fuel tank and fuel pump needed to be replaced. The vehicle was not repaired. The contact became aware of NHTSA Campaign Numbers: 23V880000 (Fuel System, Gasoline), and 23V445000 (Fuel System, Gasoline); however, the model year was not included. The manufacturer was informed of the failure. The manufacturer referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 157,000.

NHTSA ODI 11688189

The contact owns a 2019 Mercedes-Benz C300. The contact stated that while at a stoplight, there was an abnormal odor of fuel inside the vehicle. The contact stated that the vehicle failed to respond as needed. The vehicle was restarted and shut off independently. The check engine warning light was illuminated. The contact stated that the failure was related to NHTSA Campaign Number: 21V961000 (Fuel System, Gasoline). The vehicle was towed to an independent mechanic who determined that the failure was a fuel rail failure. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted and confirmed there were no open recalls on the VIN. The failure mileage was approximately 60,000.

NHTSA ODI 11656739

Po52E71- Emissions issue with crankcase. Mercedes implemented an extended warranty on various models but excluded 2019 C300, which definitely has the same issues. See below in reference to previous models. IMPORTANT EMISSION EXTENDED WARRANTY INFORMATION In our continuing efforts to assure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC (“MBUSA”) is extending the warranty coverage on the intake line assembly in certain Model Year (“MY”) vehicles listed below from the original New Vehicle Limited Warranty of 4 years/50,000 miles to 15 years/150,000 miles (whichever occurs first) due to the following condition: • Under certain circumstances, the partial-load ventilation valve (a part of the intake line assembly) may not work as intended, resulting in the illumination of the check engine Malfunction Indicator Lamp (‘MIL’). A faulty partial-load ventilation valve might also increase exhaust gas emission. Model Model Years Sales Designation C-Class 2015 – 2018 C 300, C 300 4MATIC C-Class Convertible 2017 – 2018 C 300 Convertible, C 300 4MATIC Convertible C-Class Coupe 2017 – 2018 C 300 Coupe, C 300 4MATIC Coupe C-Class Hybrid 2016 – 2018 C 350e E-Class 2017 – 2019 E 300, E 300 4MATIC GLC 2016 – 2019 GLC 300, GLC 300 4MATIC GLC Coupe 2017 – 2019 GLC 300 4MATIC Coupe GLC Hybrid 2018 – 2020 GLC 350e 4MATIC SLC 2017 – 2020 SLC 300 SLK 2016 SLK 300

NHTSA ODI 11648766

The fuel hose on the right hand side of the vehicle is leaking onto my engine. You can easily see this leak and smell it when unlocking the car in the morning. It is dangerous and could easily result in a fire.

NHTSA ODI 11638548

Leaking fuel as described in one of the previous recalls for the car. There is a fire hazard but the VIN is not listed as being eligible.

NHTSA ODI 11633699

The contact owns a 2019 Mercedes-Benz C300. The contact stated while driving, the vehicle failed to exceed 15 MPH. The check engine warning light was illuminated. The vehicle was taken to an independent mechanic to be diagnosed. The vehicle was scanned, and the mechanic retrieved fault codes indicating a failure with the high-pressure fuel pump. The contact was informed that the high-pressure fuel pump needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 34,945.

NHTSA ODI 11624818

Gas smell coming from engine area when car has been sitting overnight. Smell comes from driver's side of engine compartment. Gas smell does not happen when car is running. Smell fills up our 2-car garage causing concern when we start the car in the morning.

NHTSA ODI 11611601

The contact owns a 2019 Mercedes-Benz C300. The contact stated while driving 45 MPH, the contact noticed smoke coming from the front passenger's side wheel well. The vehicle was driven to the residence. Upon arriving at the residence, the contact raised the hood, and became that clear liquid was burning on the engine. The contact stated that after completing an investigation, it was determined that the clear liquid was the result of a leaking fuel line. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 76,000.

NHTSA ODI 11574692

On the afternoon of February 6, 2024, as I was turning into my driveway to park in front of the garage, my car unexpectedly accelerated despite my foot being on the brake pedal. Despite my attempts to brake, the pedal didn't respond, causing the car to collide with the garage door and subsequently damage storage shelves and containers inside. My mother and two brothers were passengers, returning from my mother's doctor appointment, and she became trapped inside due to the garage door collapsing onto the car. Emergency services were called, and both the fire department and police assisted in freeing my mother from the vehicle. However, the police did not file an accident report since it occurred on private property. Subsequently, I contacted my insurance agent, and the car was towed to a repair shop recommended by the dealer. Today, I was informed by the repair shop that the damages are extensive enough for the car to be considered totaled by the insurance company. Fortunately, the incident did not occur while driving on the freeway or public roads earlier that day, potentially averting a more serious accident. Nevertheless, the ordeal has caused considerable stress and sleep loss for all involved. I have since reached out to the repair shop and dealer to conduct a thorough diagnostic analysis to determine the cause of the malfunction. I've requested copies of the data captured by the On-Board Diagnostics (OBD) system and Event Data Recorder (EDR), emphasizing that this data should not be deleted without my consent. However, I am uncertain about the next steps if the insurance company removes the car from the repair shop and how to access the requested data. Upon researching online, I've discovered numerous similar cases involving Mercedes-Benz cars, with over 20 incidents reported and 11 specifically concerning the same model as mine.

NHTSA ODI 11574602

The contact owns a 2019 Mercedes-Benz C300. The contact stated that the vehicle would shut off soon after being cold started with several unknown warning lights illuminated. The vehicle was towed to the dealer where a diagnostic test was performed. The diagnostic test showed that the fuel pump was defective and needed to be replaced. The contact drove the vehicle for a few days after the diagnostic test but experienced the failure a second time. The vehicle was then towed to an independent mechanic for a second opinion where the contact was given the same diagnostic result; however, the contact was informed that the vehicle was included in NHTSA Campaign Number: 21V961000 (Fuel System, Gasoline). The contact went back to the dealer but was informed that the vehicle was not included in the recall. The manufacturer was notified of the failure and was referred to the NHTSA Hotline for assistance. The vehicle was not repaired. The failure mileage was 25,751

NHTSA ODI 11559107

When depressing the throttle, occasionally there is no response form the engine or a significant delay coupled with erratic engine revving behavior. When this happens the car has no drive power, but power brakes and steering are unaffected. The engine sits at idle speed. This has happened on multiple occasions when in or crossing traffic. The issue may present and then disappear after 15-45 seconds with no other action being taken.

NHTSA ODI 11549824

I WAS PULLING OUT OF A PARKING LOT ONTO A HIGHWAY WITH A POSTED LIMIT OF 55 MPH. AS I PULLED OUT ONTO THE HIGHWAY THE GAS PEDAL JUST STOPPED WORKING. THE CAR WAS ON BUT IT JUST WOULDN'T GO ANYWHERE. A VEHICLE COMING FROM MY LEFT AT A HIGH RATE OF SPEED HAD TO PUT ON IT'S BRAKES IN ORDER NOT TO STRIKE THE DRIVER'S SIDE OF MY DOOR. IT CAME WITHIN 2 FEET OF MY VEHICLE. I TURNED OFF THE CAR AND RESTARTED IT. WHEN I RESTARTED THE VEHICLE I TURNED OFF THE "ECO" BUTTON AND DROVE A COUPLE OF MILES BACK TO MY HOME WITH NO PROBLEMS. NOTE....I HAVE NO IDEA IF THE "ECO" BUTTON HAS ANYTHING TO DO WITH IT. THE VEHICLE HAS BEEN AT THE MERCEDES DEALER IN FORT WORTH SINCE SATURDAY JANUARY 30TH. THEY TELL ME THEY CAN'T FIND ANYTHING WRONG WITH THE VEHICLE. I'M NOT SURE WHAT THEY EXPECT ME TO DO ABOUT IT. THE CAR IS UNSAFE TO DRIVE.

NHTSA ODI 11395598