MERCEDES-BENZ Complaints

The contact owns a 2014 Mercedes-Benz GLK350. The contact stated that after reversing out of the garage, there was a large rust puddle near the rear passenger’s side of the vehicle. While the contact's wife was driving at an undisclosed speed, the vehicle made an abnormally loud clunking sound. The driver returned to the residence, and the contact also noticed the clunking sound as the driver was pulling into the driveway. Upon inspection, the contact discovered that the rear coil spring had fractured in half. The vehicle was towed to a dealer, where it was determined that the fractured rear coil spring had damaged the shock absorbers and other components. The vehicle was not repaired. The manufacturer was notified of the failure and offered to schedule an appointment. The failure mileage was approximately 82,000. The VIN was unavailable.

Broken rear subframe because of rust and corrosion with perforation. Manufacturer refused to cover the repair.

The contact owns a 2015 Mercedes-Benz C300. The contact stated that while driving at various speeds and depressing the brake pedal, the vehicle fishtailed on several occasions. The vehicle was taken to an independent mechanic, where it was raised on a lift, and the mechanic discovered that the rear subframe was severely corroded. The mechanic determined that the failure was associated with Manufacturer Communication Number: MC-10232321 (Structure); and referred the contact to a dealer for assistance. The vehicle was towed to the dealer, where the failure was confirmed, and it was discovered that the rear subframe had separated. The dealer informed the contact that the vehicle was unsafe to drive. The contact was provided an estimate for the repair and was informed that goodwill assistance would not be provided. The vehicle was not repaired due to the cost. The manufacturer was notified of the failure and informed the contact that the dealer was unreachable. The failure mileage was approximately 120,000.

The contact owns a 2004 Mercedes-Benz SL500. The contact stated that after starting the vehicle, the message "Brakes Reached Historic Threshold" was displayed, which indicated that the brake control unit had malfunctioned. Additionally, while depressing the brake pedal, the brake pedal was spongy, causing the stopping distance to become extended. The vehicle was taken to the local dealer and was diagnosed with brake control unit failure. The contact was informed that the brake control unit needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure, but no assistance was provided. The contact stated that a 25-year warranty for the failure was previously issued by the manufacturer that was associated with the failure, but was not honored. The failure mileage was 62,800.

I have experienced 4 incidents of the car accelerating on its own. I have taken it to the dealership twice and they are unable to reproduce the problem. Problems began occurring in 2025 and occurred again this past week (August 20246). In the most recent incident I was accelerating on an "on ramp". The car suddenly took hold and continued to speed up despite my foot not being on the gas. I had to drive the car to safety with my foot on the break. The moment I took my foot off the break it would speed up. The floor mat was not touching the gas in all of the instances of this occurring. The gas pedal was not stuck to anything. I nearly avoided a serious accident as where i was trying to merge was running out of a lane and a cement block was in front of me. I was also with an infant and 2 year old in my car. There have been no warning messages when this occurs.

My vehicle has about 68k miles, while driving on freeway all of sudden the car engine started to shake and check engine light came on dashboard. This engine shaking would stop when vehicle was being driven at high speed. Upon returning home I checked the DTC codes and had P300, P301 engine misfire codes. My mechanic suggested to have spark plugs and Ignition coil#1 to be changed. I bought new plugs from dealer for the replacement. When my mechanic completed this repair bit noticed vehicle still had misfire. He conducted compression test and found only 20PSI pressure is cylinder 1 and suggested a tear-down or engine replacement. I talked to another shop and described the issue and was informed that this is a common issue in Mercedes E300 to develop misfire in either cylinder 1 or 2. I found similar issues described by many owners on various forums online as well. Currently Mercedes has no recall for this issue.

Both driver and passenger seatbelts do not fully retract and remain loose. Must be manually guided back into mechanism. I see that there has been a recall for the cabriolet version of this vehicle platform but not for the coupe version. I am unsure why there hasn't also been a recall for the coupe C205 as it is the same platform and having the same exact issue. I have read on forums that there are also other drivers of the coupe platform that also have the same issue with the seatbelts not retracting so this appears to be a common issue with the vehicles safety devices.

Dashboard reading incorrectly. Blackout screen while driving. Mileage incorrectly reading. Speed limit incorrectly reading while driving the Dashboard pick up the undercarriage camera. The electricity on the car keep popping up. I have been complaining over 1yr since I lease the vehicle they only offer to trade with me paying the expenses. Gas gage not reading correctly

Moisture began collecting inside the left headlight assembly, even though the housing should be sealed. Over time, the condensation increased and the front left turn signal failed. The vehicle displayed warning messages for the turn signal, low beams, Blind Spot Assist, Traffic Sign Assist, and Active Brake Assist. The failed turn signal reduces the vehicle's visibility to other drivers and creates a potential safety hazard. A similar moisture intrusion issue was the subject of NHTSA Recall 22V-261 for certain 2021 Mercedes-Benz GLC vehicles, but this vehicle was not included in that recall despite exhibiting the same symptoms. The vehicle is available for inspection.

During a mandatory Virginia State Safety Inspection, the vehicle failed due to severe structural corrosion and perforation of the rear subframe. Because these components notoriously corrode from the inside out, the fact that the rust is externally visible and structurally failing indicates an advanced, catastrophic material breakdown.The rear subframe serves as the foundational load-bearing anchor for the rear suspension and control arms. This level of structural rot poses an immediate, severe safety hazard. Had the failure occurred while driving at highway speeds rather than being caught during an inspection, the suspension mounts could have catastrophically detached, causing a sudden loss of vehicle control, unpredictable fishtailing, and an imminent crash risk. There are absolutely no dashboard warning lights, diagnostic trouble codes (DTCs), or driving indicators to alert the driver of this structural degradation. The defect remains entirely hidden until the metal physically fractures or the vehicle fails a professional inspection. Furthermore, because neighboring states (such as Maryland) do not mandate annual safety inspections, this severe structural failure will go entirely unnoticed by thousands of drivers until a catastrophic on-road failure occurs. Mercedes-Benz has already explicitly acknowledged this exact engineering and material defect in the preceding W204 generation (C-Class models up to 2015), subsequently issuing a 20-year, unlimited-mileage extended warranty for rear subframe corrosion. However, Mercedes-Benz has arbitrarily excluded my 2015 W205 C-Class model from this coverage, despite the vehicle employing a highly similar subframe design that suffers from the exact same moisture-trapping and premature rotting failure mechanism. This represents an unaddressed, systemic manufacturing defect that poses an immediate risk to public safety. I’ve included two photos showing holes in the subframe from rusting inside out.