2012 MERCEDES-BENZ C300 Complaints

The contact owns a 2012 Mercedes-Benz C300. The contact stated that the vehicle was taken to the dealer for an airbag inspection. During the inspection, the dealer informed the contact that the rear subframe was corroded. The vehicle was diagnosed and the contact was informed that the brake lines and rear subframe needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 120,000.

The contact owns a 2012 Mercedes -Benz C300. The contact stated that upon inspection of the vehicle, he was informed that corrosion had developed on the subframe. The dealer informed him that the subframe needed to be replaced to prevent a possible severe safety failure. The contact emailed the manufacturer about the failure and received a response informing him that they could not offer any assistance. The manufacturer referred him to the NHTSA for additional assistance. The vehicle had yet to be repaired. The failure mileage was approximately 113,000.

The contact owns a 2012 Mercedes-Benz C300. The contact stated that while her granddaughter was driving the vehicle, there was a rattling sound coming from underneath the vehicle. The vehicle was later inspected by an independent mechanic who diagnosed that the rear passenger’s side wheel well had sustained severe rust and corrosion and informed the contact that the vehicle was unsafe to be driven. The vehicle was not yet repaired. The manufacturer and local dealer were not notified of the failure. The VIN was not available. The failure mileage was 115,000.

The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving approximately 2 MPH over a speed bump, there was a loud cranking sound coming from the vehicle. There were no warning lights illuminated. The vehicle was taken to the local dealer and diagnosed with failure to the rear subframe due to severe rust. The vehicle was repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 121,218.

My car smell like a gas leak. I had went to a car shop to have the car to looked at. The mechanic had told me that the fuel filter flange is leaking gas.

So here I am - another "happy" driver with a rotten subframe. Started noticing instability on the highway speeds a few months ago. Cracking noises lately. Since I use this car my very honest mechanic immediately told me that my rear subframe is completely done and I should not be driving the car until it is replaced. He quoted me $4500 (OEM parts + labor), but suggested that I take my car to MB and insist on covering the repair costs as this issue did not seem typical to him at all. I started googling and ended up here. Seems like this is a common issue and sounds like MB will replace the subframe for free in some other countries (cananda and Germany, .The dealer said the repair will cost Over $5000.00 This is a safety issue, A real big one. And the fact it's covered in other countries is so not fair. I own another mercedes and now I feel the cars are not as safe as they used to be. Please let me know what I need to do next

The rear sub frame has rusted out and broken causing the car to veer suddenly to the left during braking. A quick search of the internet reveals that this is a common problem with this car. The dealership has quoted me $4,000 for the repairs.

I was traveling at roughly 55mph when I had to make a sudden deceleration due to another vehicle pulling out in front of me. When I applied the brakes, the car unexpectedly pulled violently to the left nearly causing a head-on collision with an on coming vehicle. After Googling the symptoms/scenario, I found that this can be caused by a rusted and failed rear suspension subframe. The control arms for the rear wheels become detached from the subframe as a result. Based on my research, this seems to be an extremely common occurrence. So much so that Mercedes Canada and Mercedes Germany are replacing the defective subframes free of charge as they’ve concluded the cause to be “inadequate corrosion protection” applied to the inside of the subframe. It seems as though they’re rotting from the inside out. After learning everything about the issue, I pulled my car on to ramps in my garage and was able to confirm that my subframe had indeed failed. This is a serious safety issue which is being addressed elsewhere. During my research I was unable to find a recall or TSB related to this issue, only hundreds of people stating that Mercedes forcing customers to cover the cost to repair this extremely dangerous manufacturing defect.

Rear Subframe Rot- this seems to be a common and known issue with Mercedes’ that should be a recall. Yet Mercedes is charging almost $6000 to get this fixed at the dealer. Plus the parts are on back order for months. This is causing cars to sway when stopping. This is definitely a hazard and should be addressed ASAP!

The rear subframe on my 2012 Mercedes Benz C300 was corroded and broke. This caused the car to lose control and easily could have been been life threatening at high speeds. Mercedes Benz is clearly aware of this issue and knows this is a part defect but has not been willing to do a recall in the US even though they have done so in other countries. The dealership has told me this needs to be repaired as the car can’t be driven, so I am not happy I need to pay $5,000 out of pocket for a part defect Mercedes knows about and refuses to issue a recall even though this problem can cause a fatal accident. There were no warning signs besides hearing thumping sounds and the instability caused by the part defect when it finally failed and broke.