2012 MERCEDES-BENZ C300 Complaints

The subframe has developed extensive rust and corrosion, which I believe is a result of faulty manufacturing. This corrosion has severely compromised the structural integrity of the subframe, posing a serious safety risk. The corrosion appears to be inherent to the materials or design used in the manufacturing process, leading to the rapid deterioration of the subframe. There are also no warning lights or failure indicators for this issue. As a result, the subframe is at risk of collapsing, which could cause catastrophic failure of the vehicle's suspension and steering systems. This situation creates an immediate danger to both the occupants of the vehicle and others on the road.

My 2012 c300 has a rotted rear subframe making the car not able to be driven. It has major ,life threatening, costly damage and this issue already has a recall all over the world but not in the United States. If I can get the assistance to pay this repair, it will be gladly appreciated.

We are having issues when braking. The backend of the car wiggles when braking hard. Shop advised that the subframe on the passenger side completely broke away and on the driver side it is very rotted. They advised this is a safety issue since the broken side could pierce the gas tank. I googled this and found that there was a warranty extension for the same year and make car (document MC-10233796-0001) Spoke to the service department and they advised this did not apply to our VIN. I called the corporate number on the warranty extension letter and they advised the same. My complaint is that several other Mercedes models and makes have this issues and are covered. Why isn't ours? Based on images I found online it looks to be the exact failure mode. My son was supposed to drive the car 4.5 hours on the 4th and could have gotten into an accident or been stranded. I also read that in Germany they are fixing all vehicles with this issue.

The contact owns a 2012 Mercedes-Benz C300. The contact stated that while the vehicle was parked, the passenger’s side rear taillight was inoperable. The vehicle was taken to a local dealer but was not diagnosed or repaired since the VIN nor the model year was not included in NHTSA Campaign Number: 14V177000 (Exterior Lighting). The manufacturer was not made aware of the failure. The failure mileage was approximately 180,000.

The contact owns a 2012 Mercedes-Benz C300. The contact stated that after opening the sunroof and then attempting to close the sunroof, the sunroof failed to fully close. The contact had to open and close the sunroof several times before the sunroof closed. Additionally, the contact stated that there was water entering the vehicle from the sunroof which caused electrical failures. The contact stated that the vehicle was drivable, but the "Anti-Theft" warning light illuminated. The contact stated that several other warning lights were later illuminated, and the vehicle would not start. The contact had the vehicle towed to a dealer who diagnosed the vehicle and determined that water had damaged the driver’s side electrical wiring harness. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was approximately 169,000.

Took my car for a doorknob repair and was told the whole subframe is rotted. They told me not to drive the car on the highway. The car brakes very hard to the right and always goes right while making cranking noises. Car feels very unsafe. I paid a lot of money for this and own a 2012 c300 4matic.

This is a low mileage car with odometer reading of 25668 (less than 2000 miles per year), used sparingly and always parked in the garage. On 05/07/2024 I noticed brake fluid flowing from the left rear side of the car; on examination this seemed to come from the flexible hose that connects the brake fluid line to the brake caliper. I called my Mercedes-Benz (MB) dealer and arranged for further inspection and service. The technician identified that the brake fluid lines to the rear were both totally corroded and in need of immediate replacement. Since the lines were embedded behind the subframe it necissated lowering the subframe to access. Other parts were also severely corroded and required replacement. (see attached PDF of Invoice) The total cost of the repair was $4,592.93. The dealership applied a discount of $150.00 to this for an amount due of $4,442.93. As an engineer, I believe the material used for the brake fluid lines were unsuitable and furthermore were unprotected for the harsh environment experienced under the car, and I believe MB with all their experience in automobiles manufacturing over the years clearly should have known and forseen this fact; I do believe that MB is responsible for this premature failure of the brake lines of my car aven driven only 25,666 miles to date. I am therefore requesting NHTSA to require MB to reimburse me for the unnecessary expense of the costly repairs. It is only fortunate that this failure was identified in my garage and not on the highway. Please advise me of your resolution. Thank you.

Subframe rusted and broke. It is available for inspection. Burlington Mercedes inspected the vehicle and told me it was not safe to drive. Mercedes-Benz USA is aware of the problem. They issued a letter extending the warranty covering only the subframe to twenty years and unlimited miles. Burlington Mercedes refused to do the subframe replacement without installing all new arms, which are currently not damaged. The cost to install all new arms is $2826.54. Mercedes-Benz USA is offering a warranty extension that their dealerships refuse to honor. This needs to be turned into a recall instead of a warranty extension. This subframe issue is dangerous. It affects Mercedes vehicles dating back to 2005 and encompasses many of their models including: SLK- Class, CLS-Class, SL-Class C-Class Sedan/Coupe, GLK-Class E-Class Sedan/Wagon, E-Class Coupe/Cabrio

The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving at an undisclosed speed, he heard an abnormal sound coming from the rear of the vehicle, prompting him to pull to the shoulder of the roadway. After a visual inspection, the contact observed that both trailing arms had become detached. No warning lights were illuminated. The vehicle was taken to an independent mechanic, who determined that extensive frame corrosion had caused both trailing arms to detach. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 143,000.

While I was driving my 2012 MB C300 4Matic Sport Sedan in Nov', 2023 with history of regular maintenance, noticed a pretty load knocking noise, shudder and drifting to left a bit when it brakes from the driver's rear side especially on the highways. I took it to our local mechanic who was horrified to report that the sub frame was broken and completely rotten out too specifically rust issue with the rear suspension-rear subframe. He gets other German Cars like BMW & Audi even older and more miles in Chicago but none have rusted so much as these MB C-Class cars. Knowing the Dealers wont accept it a manufacturing defect, he was planning to repair it (no chance of wielding that thin metal sheet as the likelihood of breaking it is high). I was surprised to see 2010 Chevy Impala having a much more robust under the cover protection and no rusting with 115k miles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)