Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
Limited mileage data: 3 of 14 reports include usable mileage. There isn’t enough coverage to show a useful chart.
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
Engine. Review the 8 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
Fuel/propulsion System. Review the 2 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
Air Bags. Review the 1 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
0 crash reports0 fire reports0 injury reports
What owners actually said
14 reports
88,000 miles · Aug 7, 2026
Engine
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 ro…
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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.
NHTSA ODI #11755408
60,000 miles · May 19, 2026
Fuel System, Gasoline
The contact owns a 2021 Mercedes Benz C. The contact stated that while driving on the highway, the vehicle began to lose power, riding rough. The check engine light illuminated. The vehicle was towed to the dealer where it was diagnosed with a fuel injection failure. The vehicle read diagnostic code P1CEF85. The manufacture…
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The contact owns a 2021 Mercedes Benz C. The contact stated that while driving on the highway, the vehicle began to lose power, riding rough. The check engine light illuminated. The vehicle was towed to the dealer where it was diagnosed with a fuel injection failure. The vehicle read diagnostic code P1CEF85. The manufacturer was made aware of the issue. The approximate failure mileage was 60,000.
NHTSA ODI #11738727
Mileage unknown · Jan 20, 2026
Visibility
I am reporting a safety defect involving the panoramic sunroof on my 2021Mercedes-Benz Coop vehicle. The panoramic sunroof has malfunctioned due to an apparent design or manufacturing defect. The sunroof fails to open / close and makes grinding or popping noises which malfunctioned unexpectedly. This issue occurred without misu…
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I am reporting a safety defect involving the panoramic sunroof on my 2021Mercedes-Benz Coop vehicle. The panoramic sunroof has malfunctioned due to an apparent design or manufacturing defect. The sunroof fails to open / close and makes grinding or popping noises which malfunctioned unexpectedly. This issue occurred without misuse and during normal operation of the vehicle. The defect creates a safety concern because it can distract the driver, allow water intrusion that may affect electrical components, and/or cause sudden glass or mechanical failure while driving. The vehicle has been taken to a Mercedes-Benz dealership for diagnosis and the issue was not resolved due to denied coverage. I was informed that the repair would be costly despite the issue appearing to be a known defect in Mercedes-Benz panoramic sunroof systems. I believe this defect may affect other Mercedes-Benz vehicles with panoramic sunroofs and should be investigated for a potential safety defect or recall.
NHTSA ODI #11712287
86,078 miles · Dec 22, 2025
Engine
The contact owns a 2021 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, the vehicle stalled and failed to exceed 30 MPH, with the check engine warning light illuminated. The vehicle did not require a restart. The contact also stated that while stopped at a traffic light, the vehicle was shaking…
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The contact owns a 2021 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, the vehicle stalled and failed to exceed 30 MPH, with the check engine warning light illuminated. The vehicle did not require a restart. The contact also stated that while stopped at a traffic light, the vehicle was shaking abnormally. The vehicle was taken to an independent mechanic, where it was diagnosed and determined that there was a misfire in cylinder #2. The contact was informed that the cylinder head needed to be replaced. The vehicle was not repaired. The vehicle was then taken to the dealer, where the same diagnostic information was provided, and the contact was informed that the cylinder head needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 86,078.
NHTSA ODI #11706514
Mileage unknown · Nov 25, 2025
Engine
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 l…
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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.
NHTSA ODI #11701560
Mileage unknown · Nov 25, 2025
Fuel/propulsion System
My car had a coolant leak last year a hose broke and I have a 2021. My son’s mercedes sis the same thing on 11/23/2025. I have researched ma y others with this same issue. There should be a recall on that hose or whatever the problem Is.
NHTSA ODI #11701496
Mileage unknown · Oct 6, 2025
Fuel/propulsion System
While driving car on Sunday 10/5, it suddenly failed to respond to gas pedal pressure. The car stopped accelerating and rather slowed to 15 MPH, almost causing a car from behind to hit me in the rear side.
NHTSA ODI #11691568
Mileage unknown · Aug 6, 2025
EnginePower Train
My C300 only had about 42,000 miles and was less than 5 years old. Just after the factory warranty expired, the engine was running rough and hot, and "check engine" light illuminated. My local garage quickly diagnosed the problem as a failed cylinder head, stated that it is common with Mercedes 4-cylinder engines from about 2017…
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My C300 only had about 42,000 miles and was less than 5 years old. Just after the factory warranty expired, the engine was running rough and hot, and "check engine" light illuminated. My local garage quickly diagnosed the problem as a failed cylinder head, stated that it is common with Mercedes 4-cylinder engines from about 2017, and said Mercedes may cover it since it is a "known problem" and shouldn't happen with that mileage. I was charged $7,860 by my local Mercedes dealer, and despite multiple contacts with MercedezUSA, they refuse to acknowledge this is a problem or cover the cost, although in on-line the forums some people were arbitrarily reimbursed. There should be a recall to check for this obvious defect and should be covered. This defect can cause sudden engine failure and is a significant hazard to the driving public.
NHTSA ODI #11678865
Mileage unknown · Feb 17, 2025
Engine
Cylinder head needed to be replaced on the M264 engine at 35,000 miles. The replacement part is also known to be defective for the same reasons. This is a common defect known to the manufacturer and they have not issued a recall. My concern is that of a roadside breakdown that would endanger my wife and myself. Thank you for you…
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Cylinder head needed to be replaced on the M264 engine at 35,000 miles. The replacement part is also known to be defective for the same reasons. This is a common defect known to the manufacturer and they have not issued a recall. My concern is that of a roadside breakdown that would endanger my wife and myself. Thank you for your consideration.
NHTSA ODI #11643229
Mileage unknown · Nov 4, 2024
Back Over Prevention
Rearview camera not displaying any image when transmission is put in reverse.
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021-2023 C-Class, E-Class, S-Class, CLS, SL, GT, GLC, GLE, GLS, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle details. The fuel pump may shutdown, which can result in a loss of drive power.
Consequence & remedy
Consequence: A loss of drive power can increase the risk of a crash.
Remedy: Dealers will replace the fuel pump, free of charge. Owner notification letters were mailed on June 14, 2024. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2023070012.
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2022 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, AMG GT-Class, C-Class, E-Class, S-Class, SL-Class, GLC-Class, CLS-Class, GLB-Class, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. An error in the communication module's SIM card software can cause a mobile network connection failure, disabling the emergency call (eCall) system.
Consequence & remedy
Consequence: A disabled eCall system would prevent a vehicle occupant from contacting the emergency services call center in an emergency, potentially delaying emergency responders and increasing the risk of injury.
Remedy: The communication module software will be updated through an Over-the-Air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed July 8, 2022. Owner notification letters will be mailed in phases, on July 8, 2022, May 17, 2024, July 29, 2024, and September 27, 2024. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's numbers are for this recall is 2022060005 and 2023110006.
Additional source detail variants (2)
Communication: Auto Crash Notification
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2022 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, AMG GT-Class, C-Class, E-Class, S-Class, SL-Class, GLC-Class, CLS-Class, GLB-Class, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. An error in the communication module's SIM card software can cause a mobile network connection failure, disabling the emergency call (eCall) system.
Consequence: A disabled eCall system would prevent a vehicle occupant from contacting the emergency services call center in an emergency, potentially delaying emergency responders and increasing the risk of injury.
Remedy: The communication module software will be updated through an Over-the-Air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed July 8, 2022. Owner notification letters will be mailed in phases, on July 8, 2022, May 17, 2024, July 29, 2024, and September 27, 2024. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's numbers are for this recall is 2022060005 and 2023110006.
Electrical System:software
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2022 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, AMG GT-Class, C-Class, E-Class, S-Class, SL-Class, GLC-Class, CLS-Class, GLB-Class, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. An error in the communication module's SIM card software can cause a mobile network connection failure, disabling the emergency call (eCall) system.
Consequence: A disabled eCall system would prevent a vehicle occupant from contacting the emergency services call center in an emergency, potentially delaying emergency responders and increasing the risk of injury.
Remedy: The communication module software will be updated through an Over-the-Air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed July 8, 2022. Owner notification letters will be mailed in phases, on July 8, 2022, May 17, 2024, July 29, 2024, and September 27, 2024. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's numbers are for this recall is 2022060005 and 2023110006.
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2018-2021 CLA-Class, GLE/GLS-Class, A-Class, C-Class, E-Class, E-Class Coupe/Convertible, GLA/GLB-Class, GLC-Class, and CLS-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. The rearview camera may not display the rearview image due to a software error. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."
Consequence & remedy
Consequence: An inoperable rearview camera display reduces the driver's rear view, increasing the risk of a crash.
Remedy: Dealers will update the rearview camera software, free of charge. Owner notification letters were mailed July 15, 2022. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2022060007.
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021 C300 Cabriolet, C43 AMG Cabriolet, C63 AMG Cabriolet, C63 AMG S Cabriolet, E450 Cabriolet, and E53 AMG Cabriolet vehicles. The rear headrests may be incorrectly mounted to the seatbacks.
Consequence & remedy
Consequence: Incorrectly mounted headrests could move or detach from the seat during a crash, increasing the risk of injury.
Remedy: Dealers will inspect the rear seatback guide bushings and replace them if necessary, free of charge. Owner notification letters were mailed July 16, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021060010.
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021 C-Class, E-Class, E-Class Coupe and Convertible, GLC, CLS, AMG GT 4-door Coupe and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. A faulty electrical contact within the seat position switch may prevent the driver and passenger air bags and seat belt force limiters from properly activating during a crash.
Consequence & remedy
Consequence: Air bags and seat belts that do not perform properly in a crash can increase the risk of injury.
Remedy: MBUSA will notify owners, and dealers will replace the seat position switches, free of charge. Owner letters were mailed May 21, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021040016.
Additional source detail variants (3)
Seat Belts:pretensioner
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021 C-Class, E-Class, E-Class Coupe and Convertible, GLC, CLS, AMG GT 4-door Coupe and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. A faulty electrical contact within the seat position switch may prevent the driver and passenger air bags and seat belt force limiters from properly activating during a crash.
Consequence: Air bags and seat belts that do not perform properly in a crash can increase the risk of injury.
Remedy: MBUSA will notify owners, and dealers will replace the seat position switches, free of charge. Owner letters were mailed May 21, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021040016.
Air Bags:sensor:occupant Classification
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021 C-Class, E-Class, E-Class Coupe and Convertible, GLC, CLS, AMG GT 4-door Coupe and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. A faulty electrical contact within the seat position switch may prevent the driver and passenger air bags and seat belt force limiters from properly activating during a crash.
Consequence: Air bags and seat belts that do not perform properly in a crash can increase the risk of injury.
Remedy: MBUSA will notify owners, and dealers will replace the seat position switches, free of charge. Owner letters were mailed May 21, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021040016.
Seats
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021 C-Class, E-Class, E-Class Coupe and Convertible, GLC, CLS, AMG GT 4-door Coupe and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. A faulty electrical contact within the seat position switch may prevent the driver and passenger air bags and seat belt force limiters from properly activating during a crash.
Consequence: Air bags and seat belts that do not perform properly in a crash can increase the risk of injury.
Remedy: MBUSA will notify owners, and dealers will replace the seat position switches, free of charge. Owner letters were mailed May 21, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021040016.
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2016 - 2021 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, GT-Class, C-Class, E-Class, S-Class, CLS-Class, SL-Class, B-Class, GLB-Class, GLC-Class, and G-Class vehicles. Please refer to the Part 573 report for specific vehicle model details. The software design of the communication module may fail to communicate the correct vehicle location for the emergency call system (eCall) in the event of a crash.
Consequence & remedy
Consequence: Failure of the eCall system may result in emergency responders being dispatched to the wrong location, increasing the risk of injury following a crash.
Remedy: MBUSA will notify owners, and the communication module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. The recall began March 12, 2021. Owners may contact MBUSA customer service at 1-877-762-8267. MBUSA's number for this recall is 2021020025.
Additional source detail variants (2)
Communication: Auto Crash Notification
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2016 - 2021 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, GT-Class, C-Class, E-Class, S-Class, CLS-Class, SL-Class, B-Class, GLB-Class, GLC-Class, and G-Class vehicles. Please refer to the Part 573 report for specific vehicle model details. The software design of the communication module may fail to communicate the correct vehicle location for the emergency call system (eCall) in the event of a crash.
Consequence: Failure of the eCall system may result in emergency responders being dispatched to the wrong location, increasing the risk of injury following a crash.
Remedy: MBUSA will notify owners, and the communication module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. The recall began March 12, 2021. Owners may contact MBUSA customer service at 1-877-762-8267. MBUSA's number for this recall is 2021020025.
Electrical System:software
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2016 - 2021 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, GT-Class, C-Class, E-Class, S-Class, CLS-Class, SL-Class, B-Class, GLB-Class, GLC-Class, and G-Class vehicles. Please refer to the Part 573 report for specific vehicle model details. The software design of the communication module may fail to communicate the correct vehicle location for the emergency call system (eCall) in the event of a crash.
Consequence: Failure of the eCall system may result in emergency responders being dispatched to the wrong location, increasing the risk of injury following a crash.
Remedy: MBUSA will notify owners, and the communication module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. The recall began March 12, 2021. Owners may contact MBUSA customer service at 1-877-762-8267. MBUSA's number for this recall is 2021020025.
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2021 C300, 2017-2020 AMG C43, and AMG C63 vehicles. The front seat belts might not fully retract to their stowed position. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 208, "Occupant Crash Protection."
Consequence & remedy
Consequence: If the seat belt does not fully retract, the occupant may find the operation of the seat belt inconvenient and not wear it, increasing the risk of injury in the event of a crash.
Remedy: MBUSA will notify owners, and dealers will check the retraction function of the front seat belts and adjust the damping foam within the B-pillars, as necessary, free of charge. The recall began February 26, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021020010.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0
No exact-year investigations in this snapshot.
2021 MERCEDES-BENZ C 300 Problems, Complaints & Recalls | Skip That Year
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