2011 MERCEDES-BENZ C300 Complaints

I am contacting you about a certified pre-owned car I had purchased from Mercedes Benz Cincinnati. Following my most recent routine maintenance visit to the dealer, I received an email from Mercedes stating that they had identified that the rear subframe on my Mercedes C300 4Matic needed replacement and it was not safe to drive. It turns out that the two joints on the subframe were corroded. This type of a problem is not expected for a professionally maintained certified car by Mercedes that is at 58,481 miles. The issue has nothing to do with standard wear and tear, or user negligence, and it stems from the material used in the specific component. There is no other area on the vehicle that is displaying even the slightest amount of corrosion. The mechanic said that this is to do with the properties of the materials selected for the manufactured part, they have been seeing many cars of the same year with the same exact problem, and if the subframe joints were to break while the car is in motion, it could potentially cause a fatal accident. There were no warning lamps, message or symptoms of the problem prior to the failure. I contacted Mercedes and asked them to address this problem. After months of back and forth, I was told there were no safety recalls, and the car was out of standard warranty period. I was also told that the part was not currently available (and was on back order). As you may know, the subframe's job is to distribute high local loads over a wider area of the body structure and its failure could result in fatal accidents. The internet is full of customer complaints on this issue, yet there are no safety recalls issued.

I am reporting a big safety hazard issue on these Mercedes C300 model year 2011. The suspense bracket just breaking off with obvious no visible issues. The suspension support bracket is got rotted with rust from inside out and broke off while driving on the highway. The issue was obvious when I braked suddenly and the car just pulled itself to the right side. This could easily cause an accident. I reported the incident to Mercedes and they told me to report to NHSTA and they cannot do anything. Once home and jacked up the vehicle I found that the bracket was completely off the frames and it did hit the gas tank causing a dent in the tank (a big safety issue) seam. I googled the issue and it seems like it is a known issue with these models and Mercedes have not recalled or fixed this issue on any vehicle. I have attached pictures of the broken bracket. Thank you

The rear subframe rusted out at 115k miles and it completely cracked. No other sign of rust on the vehicle. Kept in the garage. Definite safety issue.

The contact owns a 2011 Mercedes-Benz C300. The contact stated while driving approximately 40 MPH and depressing the brake pedal, the vehicle was pulling to the right. The vehicle was taken to an independent mechanic who discovered that the rear subframe of the vehicle had sustained severe rusting and corrosion causing the vehicle to pull to the right while braking. The contact was advised that the subframe needed to be replaced. The vehicle was not repaired. The manufacturer and local dealer were not notified of the failure. The failure mileage was 170,000.

08/15/2022 (date statement was wrote not date of incident) While driving into work at 50 miles an hour, traffic started to slow. While applying brake heard loud pop and vehicle rear end lounged right making steering difficult, I immediately released the brake and control came back I then gently applied the brake again to slow vehicle and felt slight clump from rear. This was very disconcerting my vehicle never had performed in that manner which made me feel very uncomfortable continuing driving, I had mechanic look at vehicle and was told the rear subframe had rusted and the rear left control arm broke away from frame??? My vehicle is very well maintain and just a little over 11 years old. Feeling belittled I began investing Mercedes’ forums and found this has been an issue with some of not all models and nothing has been done to correct this defect. I contacted Mercedes’ Benz and the service department knew exactly what it was and stated the is no recall on these failing subframe due to rust. This is a very serious safety issue due to the fact of loosing control of the vehicle when this component fails possibly causing serious injury or even death. To put insult to injury Mercedes has no plan to replace it and it’s left to the consumer to replace this non maintenance item. Looking into forums about this issue these subframes have failed at almost every odometer mileages, particularly the w204 chassis 2008-2014. A safety recall should be advised to the consumers whom own such vehicles!! Safety First!!!!!!!!! Respectfully, [XXX] INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).

1. Rear Subframe of the car rusted out, causing car to suddenly jerk to the right while braking. as inspected by my mechanic, the driver side part of the rear subframe is also about to fail as well 2. The sudden jerky movement can probably cause me to lose control and possibly crash into another vehicle, potential hurt myself and other cars around me 3. Yes, the problem has been reproduced and confirmed by an independent service center 4. The vehicle or component has not been inspected by the manufacture, police, insurance representatives. It's only been inspected by my mechanice. 5. No warning lamps or symptoms appeared prior to subframe failure

The car started fishtailing slightly when the brakes were applied at speeds around 25 MPH. First it was taken to a Mercedes dealership on June 24th where they said it need a sway bar and tires. They were not sure that would address the issue. When we went to get tires, the tire person said the control arm was connected to nothing in the rear. The rear subframe was rotted to the point that there was not a place to even weld it back on to and needed to be entirely replaced. The fact that Mercedes missed it is shocking in itself, I can only assume (we bought the car used) it was rotted from use in winter weather before we got it. The repairs have been estimated to cost between $2200-3800-.

I took the car to Mercedes for service and they found that the rear suspension frame had extensive rust and recommended that it should be replaced. The car only has 87,000 has been garage kept since buying the car in 2013 and has been serviced my MB. The frame has two quarter size holes at the same location on the left and right sides. MB was made to recall this in both Canada and Europe. MB stated that this is a known issue with this car. Why has the NHTSA not forced MB to recall this car? MB knows that if part fails the entire rear drivetrain separates from the car. My understanding is this effects most C-class E-class cars, plus the repair is over $4,000.00 This should be on MB not the consumer.

The rear subframe is rusted and broken, alignment is out, and steering wheel is off centered. Given the history of this model car, it has been under recall in multiple countries outside the United States. This is a common and very dangerous issue that needs to be addressed in the United States because if you call any auto shop or Mercedes they all say it is a common problem with 2008-2014 C-class models. When you look up this issue with this car it has multiple threads saying that the rear subframe has rusted and broke when it is not supposed to.

The contact owns a 2011 Mercedes Benz C300. The contact stated while driving 35 MPH, the brake pedal was depressed abruptly and the vehicle fishtailed off the road. The contact stated no warning light was illuminated. The contact was able to continue driving to her destination. The contact took the vehicle to an independent mechanic and was informed that the brake calipers needed to be replaced. The vehicle was not repaired. The contact called the local dealer and made them aware of the failure. The contact continued to experience the failure. The contact took the vehicle back to the independent mechanic and was informed that the subframe was corroded. The vehicle was not repaired. The manufacturer had not been informed of the failure. The failure mileage was approximately 160,000.