Mercedes-Benz C-Class Complaints

3,817 consumer complaints on file.

#11719197February 19, 2026
UNKNOWN OR OTHER
Spontaneous explosion of sunroof while car is in motion on the expressway 83 and could have caused an accident while my daughter was driving
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11718583February 17, 2026
ENGINE
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11717513February 12, 2026
ELECTRICAL SYSTEM, ENGINE, AIR BAGS
The contact owns a 2010 Mercedes-Benz C300. The contact stated that the battery and alternator were being drained. The check engine warning light was illuminated. Additionally, the front air bag sensor message and a fog light message were displayed. The vehicle was towed to an unknown local dealer; however, the dealer was unable to determine the cause of the failure. The contact then reached out to Mercedes-Benz of Tysons Corner Service and Parts, located at 8545 Leesburg Pike, Vienna, VA 22182, and was informed about a diagnostic test to determine the cause of the failure. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 97,000. The VIN was not available.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11716937February 10, 2026
STRUCTURE
The contact owns a 2016 Mercedes-Benz C300. The contact stated that while driving approximately 20 MPH and turning the steering wheel to the right or the left, there was an abnormal clicking sound coming from the rear of the vehicle. There was no warning light illuminated. The contact had taken the vehicle to a local dealer where it was diagnosed and determined that the rear sub frame of the vehicle had severe corrosion and needed to be replaced. The contact was advised by a service technician that there had been a recall for corrosion failures, but the year and the model were not included. The vehicle was not repaired. The manufacturer was informed of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 130,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11716768February 9, 2026
ELECTRICAL SYSTEM:INSTRUMENT PANEL:SPEEDOMETER/ODOMETER
Odometer Fraud. The contact purchased a 2019 Mercedes-Benz C300. The contact stated that after purchasing the vehicle, it was discovered that there was a mileage discrepancy. The vehicle was a dealer sale. The contact stated that at the time of purchase, the odometer reading was approximately 54,000 miles. At the time of registration, the mileage was approximately 54,000 miles, and the same mileage was also reflected on the Carfax report. The contact stated that the mileage discrepancy was later discovered through a public report with the Federal Trade Commission (FTC); however, the mileage was not provided. The contact stated that the mileage discrepancy occurred after two OTA’s were performed on the vehicle. The contact stated that during the OTA’s on the vehicle, the mileage was changed. The contact stated that several documents with the mileage discrepancies were listed with the FTC. The contact also reported the discrepancy to the Department of Motor Vehicles.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11716863February 9, 2026
FUEL/PROPULSION SYSTEM
Strong fuel smell in cabin Can maybe cause a fire
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11716648February 9, 2026
ENGINE
my car overheats badly and shakes and it is starting to smoke from the hood in snowy conditions
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11715179February 2, 2026
ELECTRICAL SYSTEM
ESL emulator is bad. Keeps no crank Steering lock Also sunroof water spouts are not working as they should they do no open to release water.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11714200January 29, 2026
FUEL/PROPULSION SYSTEM, ENGINE
fuel lines/ clamps defective causing a fuel leak. vehicle could catch on fire and fumes are extremely strong inside the cabin. issue confirmed by Mercedes dealer, mentioned there is an extended warranty up to 120,000 miles. rejected mine because i was at 120,300 miles. had to pay out of pocket. no warning lights or anything just the really strong smell of fuel and fuel range dropping. this is a very common issue thats known and should be a recall.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11713745January 27, 2026
STRUCTURE:BODY
I have been informed by my dealer's service unit that the rear subframe of my car (2015 Mercedes C class) is rusted with holes. My understanding is that this can affect the integrity of the structure and cause problems while driving. According to your website [XXX] ) , this should be covered under a warranty extension. However, Mercedes says that my car is not, and to fill out this form if I believe it should be. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11712884January 23, 2026
FUEL/PROPULSION SYSTEM
1. What component or system failed or malfunctioned? The low-pressure fuel feed line (Part No. 274-070-35-00) and its associated clamps connected to the high-pressure fuel pump. Availability: State: The defective hose is currently on the vehicle and is available for inspection. If the repair proceeds, I request the dealership to retain the failed part for my inspection. 2. How was your safety or the safety of others put at risk? The failure resulted in raw fuel leaking directly into the engine compartment. This creates an immediate and severe fire hazard, as gasoline is being released near high-temperature engine components. Furthermore, the strong odor of gasoline entered the cabin through the HVAC vents, exposing passengers to toxic fuel vapors while the vehicle was in operation. 3. Has the problem been reproduced or confirmed? Yes. The defect was confirmed by Mercedes-Benz of Orange Park (Dealer Code: 64111). The technician performed a 'cold start' inspection and verified fuel leaking from the low-pressure line to the high-pressure pump. > Note: My service advisor's admitted: Yes sir we will do the hose. 4. Has it been inspected by the manufacturer, police, insurance, or others? Answer: The vehicle has been inspected and the failure documented by an authorized Mercedes-Benz dealership technician. It has not yet been inspected by insurance or police as no fire has occurred yet; however, the dealership has identified the part as defective. 5. Were there any warning lamps or other symptoms prior to failure? There were no warning lamps or dashboard messages. The primary symptom was a pungent smell of raw gasoline inside and outside the vehicle, specifically during cold starts. These symptoms first appeared recently [January 3rd, 2026] and became persistent as ambient temperatures dropped.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11712677January 22, 2026
ENGINE
While driving on highway, the engine light came on, a diagnostic test was performed by dealer, oil control valve defected) This could cause engine to lock up while driving, a serious safety concern. I contacted Mercedes Benz corporate office seeking help, because of factory defect. They're not assisting me with this extreme safety matter!!
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11712823January 22, 2026
AIR BAGS
I purchased this vehicle on December 26, 2025 from an authorized Mercedes-Benz dealership. Shortly after the purchase, I discovered an issue related to the airbag system, which indicates a potential safety defect. At the time of purchase and during the test drive, the vehicle was already turned on, and no warning or disclosure was provided regarding any airbag malfunction or warning message. The issue became apparent only after the purchase. I later brought the vehicle in for repairs. While some repairs were performed, the airbag issue was not fixed and remains in the same condition as before. The dealership is now refusing to repair the airbag system at no cost and is insisting that I pay for the repair, despite the fact that this defect appeared immediately after purchase and was never disclosed to me. I believe this represents a serious safety concern, as a malfunctioning airbag system may fail to protect occupants in the event of an accident. I also believe the vehicle was sold to me with an undisclosed safety defect. I am requesting that this issue be formally reviewed and investigated.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11712012January 20, 2026
FUEL/PROPULSION SYSTEM
Strong gas odor coming from vent when heat and AC is on. Odor was causing dizziness and had to drive with window open or vent off. When opening the hood gas odor was also present. Brought to the mechanic and found fuel lines leaking. Went online and found out this is a very coming problem. I had to spend $657. to repair. Mechanic stated Mercedes issued a service bulletin but not a recall.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11712059January 20, 2026
SUSPENSION, UNKNOWN OR OTHER
Failed/Malfunctioned Component: Rear subframe (structural/chassis component) exhibited advanced corrosion (perforation/rust-through), compromising structural integrity and alignment/handling. Availability for Inspection: Yes. The vehicle and the subframe are available for inspection upon request. I can provide photos, videos, and repair estimates if needed. The corroded subframe is fracture and detach suspension mounting points, which may lead to: Sudden loss of vehicle stability or control (especially during braking, cornering, or over bumps). Unpredictable alignment changes causing pulling, vibration, or abnormal tire wear that can escalate into a loss-of-control event. Increased stopping distance and potential for wheel misalignment or collapse, raising the risk of a crash involving occupants and other road users. I limited driving/use due to the risk; issue is a structural safety concern rather than cosmetic. Confirmation: Yes on multiple visits since Oct 2023 -Yes—diagnosed and documented by Mercedes-Benz of Silver Spring on Oct 2 2023, Nov 2023 and Dec 2025. Technician confirmed severe corrosion/rust perforation on the rear subframe requiring replacement. No No
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11712287January 20, 2026
VISIBILITY:SUN/MOON ROOF ASSEMBLY
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11711917January 19, 2026
SERVICE BRAKES, WHEELS
Rear brakes backing plates rotted prematurely despite garage kept and well maintained status. While driving, noticed loud scraping and grinding noises from the rear left wheel. Took to mechanic and he found severe rust, with deep corrosion and flaking "rotted". He said I was lucky because this was very close to causing the entire brake assembly to fail, which would lead to serious braking problems or "locked out wheel" and loss of control on a highway which would have put me and others at risk. Had similar rust issues with this car that were fixed in the recent past including rusted brake lines and rusted rear subframe. There is definitely something wrong with the manufacturing as the rear subframe had been recalled and got it fixed that way less than a year ago.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11710517January 12, 2026
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING, FORWARD COLLISION AVOIDANCE: WARNINGS
Refer to Mercedes Complaint letter dated August 21, 2025. Refer to EDR report of the crash Mercedes Benz is claiming no responsibility for the failure of Active Brake Assist (ABA) during a frontal impact collision that resulted in the car total loss. The sensors also didn't work resulting in no alert to the driver and nothing recorded on the car camera system.
Crash:
Yes
Fire:
No
Injuries:
0
Deaths:
0
#11710171January 11, 2026
ELECTRICAL SYSTEM, SERVICE BRAKES, FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
points: ⸻ While driving, the vehicle displays the warning “Active Brake Assist Functions Limited – See Operator’s Manual.” The message appears during normal driving and does not go away. This warning indicates that the automatic emergency braking / Active Brake Assist system is limited or disabled, reducing a critical safety feature designed to help prevent or mitigate collisions. This creates a safety risk because the vehicle may not automatically brake in an emergency situation. The warning appeared suddenly while driving, with no visible obstructions, weather conditions, or damage to sensors. Restarting the vehicle does not consistently clear the message. The issue has not yet been inspected by a dealer or repair facility. The cause of the malfunction is UNKNOWN, and the vehicle is available for inspection.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11709871January 9, 2026
ENGINE
Check engine light comes on, Error Code P052E, after a lot of research, this is a known defective part by Benz. Huge safety issue not addressed by them. Very costly to fix for a customer. There is a new and improved replacement part from Benz indicating they are aware of the faulty old parts that are currently in those cars but yet they have failed to do a recall.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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