2012 Mercedes-Benz C-Class Complaint Log

Subframe corroded/rusted out. Car is in excellent condition with no other rust or corrosion. Car has 58,800 miles and regularly maintained by dealer. Took car to TireDiscounter because of noise. Mechanic put car on lift and reviewed corrosion and other damaged cause by failed part. Mechanic called MB service department and was told that parts on 5- 6 months back order because of this issue. But no recall even though problem is wide spread. Rear tires and gas tanked damaged by loose subframe.

Diagnosed with broken rear sub frame: "Broken rear sub frame, left side lower link is broken off and contacting Fuel Tank. Rear tires are also bald and care is unsafe to drive". Recall in Canada, but not USA. Sub frames on backorder until January 2023. I have three years of payment left, and am now being quoted 6,300 from the MB Service Ctr in Wilmington DE to fix this problem. Again, the items are on backorder due to heavy demand. Im a single mom we depend on my car to get us to work. This is the ultimate catch 22 as the car is extremely dangerous to drive and put us all in serious jeopardy - but no one will take this broken car as a trade in. I am forced to drive the vehicle while I wait for backordered parts and pray that I can get a loan to pay for it. "".....and contacting the fuel tank".....

I’m filing a complaint due to a concern regarding the rear subframe of my vehicle becoming rotted/rusted out and falling apart at any time. This is due to a Mercedes Benz manufacturing issue where they tried cost cutting which turned out very poor quality materials for this very important assembly. I have researched online about this problem, and turns out, it is very common with this body style c300 ('08 - '14). There are hundreds, if not thousands, of individuals within the USA who are having this exact same issue with as little as 60,000 miles. Most are happening around the 90,000 mile mark however. They primarily mention in many online forums how scared they were when it happened and how lucky they are it didn’t cause a major accident…yet. My car only has ~110,000 miles and is just about 10 years of age. This issue should never happen for a vehicle with such low miles and such a short life, especially from a prominent and distinguished automotive company. This is a Huge Safety Concern, and I am Scared that this subframe will fail without warning and at a high speed, which can likely cause me to be involved in a major accident where people are killed or seriously injured. It is astonishing how this subframe was not recalled by now and how Mercedes USA has not taken responsibility for this. This issue needs to be addressed and recalled Immediately before people are killed or seriously injured, and before more of these parts break. Please look into this very soon as this is a very serious matter.

The esl/eis failed. Turned car off and after coming back to try and turn it on, it didn't work. Steering wheel was locked and car wouldn't engage with key. After checking with mechanics and checking online, I discovered that it is a frequent issue that happens with no warning whatsoever. Which is quite worrisome to think the Steering wheel could lock at anytime without notice. My car is a 2012 Mercedes c250 coupe.

The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving 25 MPH going downhill, the rear end of the vehicle shifted independently to the right. The contact stated no warning light was illuminated. The contact was able to continue driving at a slow speed to her destination. The contact stated her husband inspected the vehicle and became aware that the rear subframe cross member had fractured due to corrosion. The vehicle was not diagnosed or repaired. A dealer was not contacted. The manufacturer had been informed of the failure. The failure mileage was approximately 149,000.

The contact owns a 2012 Mercedes-Benz C300. The contact stated that the vehicle was unable to start-up as needed. The vehicle was towed to the dealer where it was diagnosed with a faulty steering column sensor that needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was 104,692.

The W204 subframe of my Mercedes Benz C Class is failing and in need of repair, this should not be happening to a car with less than 80K miles on it. My local auto repair shop which exclusively services Mercedes Benz currently has two vehicles with the same issue and informed me that the subframe part is currently out of stock due to the number of failures. This issue has caused a recall in other countries. What is the NHTSA doing about this issue. I will be contacting my congressional representative today as well.

Dealer states that the rear subframe has rusted and degraded to the point of requiring full replacement. The car is 10 years old with 98,000 miles on the odometer. This is premature degradation of an essential component.

The contact owns a 2012 Mercedes-Benz C300. The contact stated that the vehicle was taken in for a routine service check at the dealer and the mechanic informed her that the rear subframe was rusted and the vehicle was unsafe to drive. The contact was informed that the part was on back order. The manufacturer was not contacted. The failure mileage was 119,000.

the Rear Subrame CRACKED while Driving, Almost causing a Major accident with my son in the car as well. This seems to be a MAJOR problem being overlooked and ignored by Mercedes Benz . This repair is going to Cost me $ 3000-$ 5000 Dollars. and the Replacement Subframe is Impossible to find and on Back order ! so Now I'm without a Vehicle for God knows How long ?? I Feel there is No Doubt this is a Defect and Should be Covered by Mercedes Benz and a Recall ! How is this not being investigated is Really Scary. How can a Frame or a Car just Crack ? That's Not safe for ANYBODY !

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.

- Right Rear Subframe; Yes, available for inspection. - My mechanic told me that driving the car more than 2 miles or at a high rate of speed was very dangerous. He told me there that if the car braked quickly or was driven at a high rate of speed that there was a very good chance of an accident. There is a risk of the right control arm detaching from the frame; this could cause the car to be uncontrollable with the right rear wheel and control arm detaching from the vehicle. - Yes, the issue was confirmed by my mechanic, who works at an independent service center. - No. - There were no warning lamps or messages. I had begun to hear a loud clunking noise, usually when braking.

Took my car in for inspection at the Mercedes dealership. They advised the rear subframe was rotted or rusted. This occurred from the inside. The vehicle is garage kept. They advised Mercedes has no re-call on the issue in the United States. They are covering the issue outside the US. This is a major safety issue.

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.

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 C350. The contact stated while driving at an undisclosed speed, the sunroof glass shattered and landed on the sunroof cover. There was no impact on the sunroof that could have caused the sunroof to shatter. The contact and his daughter did not sustain any injuries. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 75,000.

The contact owns a 2012 Mercedes-Benz C300. The contact stated that upon taking his vehicle to a dealer for maintenance repairs; he was provided an estimate for the repair of corrosion to the rear subframe of the vehicle. Upon investigation, the contact discovered that the failure could lead to a potential braking system failure. The manufacturer was notified of the failure and informed him that there were no recalls on the vehicle. The vehicle was not repaired. The failure mileage was approximately 97,000.

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.

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.

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!

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

I ran off the road and my rear suspension sub frame literally broke in half. Upon further research I’ve learned that these parts are faulty and several people have had theirs rust completely in two. Mine had lots of rust damage and that is likely what caused the damage to mine when I ran off the road (MINOR impact that should have never caused that much damage). Mercedes has recalled this part in several countries including Germany and Canada. When I drove home after running off the road my car was nearly impossible to drive. It was jerking all over the road and when I tapped the brakes the rear end of the car would come up off of the road (into the air)! This was in June. It’s now September and I still have not been able to obtain a part from Mercedes. So many people are having this issue with their vehicles that the part is on back order until Q1 of 2023. This is a part of the cars sub frame that is rusting in two! One would argue a broken sub frame is dangerous. And it’s such a prominent issue the part is on back order. Furthermore, Mercedes has changed the type of metal used in replacement parts, which is an acknowledgment of the parts defect.

During a routine oil change Mercedes mechanic discovered our rear subframe is rusted on both sides and needs to be replaced. This is apparently a well known problem, and Mercedes will replace this for free in Germany, but has not recalled the subframes in the US. Mercedes created a new OEM part as the replacement part, proving the original part is faulty. However Mercedes does not have enough parts ane every mechanic we have spoken with has several subframes on order for months at a time. We have waited 9 weeks at this point. Many Mercedes drivers subframes have broken making the cars undrivable.

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.

AUTO IS LESS THAN 100K MILES EXCELLENT CONDITION HAD THE TURBO GASKET GO BAD ON THE AUTO. OIL LEAKING IN THE MAIN ENGINE COMPARTMENT AND ON GROUND DUE TO THE GASKET ISSUE. COULD CAUSE DAMAGE TO ENGINE AND TURBO. GASKET SHOULD NOT HAVE GONE BAD. WHILE AT THE MECHANICS SAME ISSUE WITH THE SAME EXACT MODEL OF MERCEDES, NOT SURE THE YEAR BUT IDENTICAL BODY STYLE. REPAIRS WERE COMPLETED ON 06/07/22 COST THROUGH MECHANIC $465.00 ANY TIME DUE TO PASSING OR EXCELARTION THE ENGINE WOULD MISS OUT AND LOSE POWER FOR THE PASSING OR ESCELARTION.

Part number: 207-350-97-02 This is the sub frame part number, during routine maintenance i found a cracked rear sub frame mount. Upon googling, there are hundreds of owners with that same problem. Cars with milage ranging from 40,000-150,0000 with the same issue. Under hard braking the car is unstable. When I called the MB dealer to inquire about the problem they did confirm that the problem is known but is not a safety recall and the repair bill is near $5,000. So Mercedes, confirmed it’s a known issue with a faulty part, confirmed it was a safety issue with the 2008-2012 Mercedes c300 and is not covering it.

The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving 70 MPH, there was an abnormally loud sound from the rear of the vehicle. The contact lost control of the vehicle. There was no warning light illuminated. The contact was able to continue normal driving once he regained control of the vehicle. The contact scheduled an appointment with an independent mechanic for the vehicle to be inspected. The contact was informed that the rear subframe had detached from the passenger’s side of the vehicle due to severe corrosion. The dealer was notified of the failure and informed him that there were no recalls related to the failure on his vehicle. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 138,000.

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.

The contact owns a 2012 Mercedes-Benz C300. The contact stated that while the vehicle was receiving a routine maintenance, she was informed that the rear sub frame was rusted and had two holes. The vehicle was diagnosed that there was a transmission leak and the rear sub frame needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure but no additional assistance was provided. The failure mileage was approximately 88,000.

Major rust in the welded joints of the Steel subframe. Long crack development along the seams, could have led to catastrophic lost of control of vehicle if the breaks were not found. This is an apparent flaw with the C-Class Mercedes Benz and quite surprising to the Service Reps at my dealership that this has not been a recall issue, as they’ve replaced many. The repair is quite costly, over $5,000. There were no symptoms, warnings or messages. This was found when the vehicle was in for a 10k service. I have a video sent by the technician that show the inspection of the vehicle.

The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving approximately 65-70 MPH, he heard abnormal clicking sounds coming from the rear of the vehicle. Additionally, the contact stated that while driving and depressing the brake pedal to come to a complete stop, the vehicle swerved while stopping. The vehicle was taken to an independent mechanic where it was diagnosed that the rear driver's side subframe was severely corroded and fractured and needed to be replaced. The dealer was notified of the failure and informed the contact that the vehicle would be repaired at his own expense. The vehicle was not repaired. The manufacturer was notified of the failure but did not provide any assistance. The failure mileage was approximately 75,000.

The rear K frame on Mercedes Benz C300 totaly rusted through and broke apart causing the entire rear of vehicle to rest upon the fuel tank. The failure also caused stress on rear brake lines. The vehicle is 10 years old with 90,000 miles purchased brand new and garaged. Mercedes has performed a recall on Canada vehicles but no USA vehicles. This is total negligence. This is going to cause a fatality. Either a vehicle will catch fire or brake lines will fail and cause an accident. The vehicle is known by the dealers to have this damage/failure. I googled and found numerous cases. Mercedes was not willing to stand by the vehicle and repair. This should be a recall like it is in Canada. I was quoted $5000.00 to repair by Mercedes.

Failure of rear subframe causes car to lose control. Only found out about the problem after I received a Mercedes extended Warranty in mail March 2023, roughly 6 months after OEM Undercarriage failed and forced me to purchase another Undercarriage in cash/no insurance involved because part back ordered for many months. Car thus inoperable for roughly 4 months. At moment of the OEM failure, total loss of control. Mercedes refuses to reimburse for cost of replacing undercarriage regardless of the fact that failure occurred before notification and regardless of fact that part unavailable for months

From the mechanics notes: Four-wheel alignment could not be completed. Attempts to align the rear axle were unsuccessful due to flexing/movement in the rear suspension. A brief road test revealed occasional suspension “clunking” coming from the rear of the vehicle. Close examination of every suspension component mount revealed heavy cracking on the passenger side lower drag link subframe mount (see emailed image). The driver’s side low drag link mount location is also starting to show signs of overstress and rust/flaking. This is a known design defect that has been the subject of a manufacturer’s recall in Canada. Given the substantial safety impact of this design defect/failure, it is expected that a US recall will be forthcoming. Proper repair of this failure involves removing the entire rear axle/subframe assembly and either rebuilding/re enforcing the subframe or replacing it with a new unit and transferring all the suspension components to the new subframe. A current check of subframe availability is showing NLA (no longer available) status from Mercedes wholesale dealers – likely due to recent high demand and inability to satisfy that demand. This supply issue may also be playing a role in Mercedes’ failure to address this high level safety issue with a US based recall campaign. The manufacturer may be ramping up production of this component to address anticipated need – waiting to announce a recall when it has sufficient parts on hand to execute the campaign. It is strongly recommended that you file an NHTSA complaint for this issue and limit driving until the problem is rectified either independently or under the auspices of a recall campaign. The passenger side rear drag link has not yet completely separated from the subframe but is likely to do so soon which can result in an accident or loss of control as this critical suspension link is responsible for maintaining steering direction of the right rear wheel.

I took my vehicle in for a state inspection and was informed the rear subframe was rusted/rotting and on the verge of detaching. Had this happened while driving, the results could have been catastrophic. The vehicle cannot be driven until this $4K dollar repair is completed. Upon speaking with the mechanic, this is a well known issue within Mercedes. Had I not asked for an alignment, this would have remained undiscovered until it inevitably broke off while driving the vehicle. This is a major safety issue and a safety recall should be issued.

I drove over an object on the highway and noticed my car veering left and wobbly when turning. A week after, it is squealing like a load of piglets in my trunk whenever I go over a bump, then my battery light came on and I took it to the shop and contacted my insurance, who denied my claim saying it was 'wear and tear'.

While performing service inspection, technician found REAR SUB FRAME RUSTED AND READY TO BREAK. Told they needed to show me the problem on the lift, as it was a serious SAFETY ISSUE and should be IMMEDIATELY REPLACED. Dealer and service acknowledged that this is a KNOWN and WIDESPREAD PROBLEM in C Class vehicles. Cost to replace quoted at $4200. No warning - thankfully inspection found before I was in a serious accident! Mercedes should issue recall for failed/corroded frame. Not the "safe" vehicle that Mercedes claims. (Car has been dealer serviced regularly, garaged, and 34,000 miles.) Owners shouldn't have to suddenly come up with $4,200 in order to drive their seemingly normal car. DANGEROUS.

The contact owns a 2012 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, he depressed the brake pedal and the vehicle swerved. Upon inspection, the contact noticed that the rear passenger's side sub-frame was corroded and the stabilizer arm had detached from the sub-frame due to corrosion. The vehicle was taken to an independent mechanic who diagnosed that the sub-frame needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 100,000.

Premature subframe rust, causing the vehicle to swerve when brakes are applied looks to be a trend: https://www.benzworld.org/threads/2012-c300-rear-subframe-any-updates-on-recall.3086018/page-6

While driving, engine stopped, could not steer.. Looks like a defective Electronic Ignition Switch or steering lock! It seems to be a common problem on these cars!!! The car would not start. After 8 attempts, I was able to start car but was afraid to drive it. Could have been a disaster.

2012 C250 has a known defect with high pressure fuel pump. I personally have had an intermittent issue where vehicle will unpredictably stop working under heavy throttle and enter limp mode as the computer throws a fault code. This results in loss of power after the code making vehicle unpredictable and dangerous in passing situations. It leaves you stranded in the passing lane with oncoming traffic with a vehicle that will not accelerate. I have submitted a request multiple times with Mercedes benz corporate who has declined my submission. This issue has been ongoing since 2016. They have offered an extended warranty on the vehicle 10 years and 120,000 miles as they know there is a defect. It is dangerous and needs to be covered for all of the affected vehicles.

Per the dealership in connection with a regular service, the rear subframe rusted out and became structurally weak and was a safety hazard. The problem was confirmed and repaired by an independent repair shop. From Google searches, this issue does not appear to be an uncommon problem. Car is garaged and receives regular underbody washes for road salt.

The engine in my car died and after inspection by a Mercedes mechanic they concluded the failure was caused by faulty camshafts that have been common in the year and model this car. Mercedes has issued and extended warranty to cover the repairs recognizing this was a manufacturing issue but they are refusing to cover the full cost of repairing my car.

Rear subframe failure caused me to loose control of vehicle almost resulting in a serious highway accident. Rear driver side stabilizer subframe mount was completely corroded and broken away from the subframe. There is no other significant corrosion on the subframe. MB claim normal corrosion however the pictures tell a different story.

Vehicle was in for state inspection at an authorized inspection station. It failed inspection due to severely rusted and deteriorated rear K-Frame which had to be replaced to pass inspection. This is a major defect I feel caused by manufacture negligence. There were no warnings, messages or any signals indicating a problem. This issue could have severely caused an injury or even death had it not been detected by the mechanic inspector. Mechanic stated to me that he had replaced several of the rear K-Frames in the last year on this make and model.

Dear Sir/Madam, I am writing to file a formal complaint against the Fletcher Jones Mercedes-Benz franchise located in Ontario, California and Mercedes-Benz USA , specifically addressing the issue of the dealership closing the recalls and not honoring the warranty recall on my 2012 Mercedes C250, even though I have received multiple automotive part recall notices for my vehicle. Please see the attached files below for the full story. Thank you for your time.

Dear Sir/Madam, I am writing to file a formal complaint against the Fletcher Jones Mercedes-Benz franchise located in Ontario, California and Mercedes-Benz USA , specifically addressing the issue of the dealership closing the recalls and not honoring the warranty recall on my 2012 Mercedes C250, even though I have received multiple automotive part recall notices for my vehicle. Please see the attached files for more details.

Electronic Steering Lock (ESL) fails and your key fob nor your keyless go button will function, rendering your car unable to start...! Usually it's the cheap toy motor that engages the moving tab that locks and unlocks the column and communicates to the ignition to start the car... You get only a message to "remove your key" and the dash lights will not come on nor can you start the vehicle... Mercedes is aware of this, as there are thousands of complaints on this ESL issue... Mercedes needs to issue a recall and do away with this faulty ESL module...!!!! Oh by the way, they charge $1500+++ to fix it...

The contact owns a 2012 Mercedes-Benz C300. The contact stated her son was driving approximately 60 MPH and noticed that the steering wheel was crooked and vibrating. The driver was manually turning the steering wheel for the vehicle to drive straight. The driver also noticed that while depressing the brake pedal, the rear of the vehicle was shaking going from left to right while coming to a complete stop. The driver took the vehicle to an independent mechanic to be inspected and was informed that the rear driver’s side subframe had separated from the vehicle due to extreme rust. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 115,000.

The contact's wife owns a 2012 Mercedes-Benz C300. The contact stated that upon taking the vehicle to the dealer to be serviced, he was informed that the subframe was severely corroded and could fracture. The manufacturer was notified of the failure and advised the contact that they could not assist as the vehicle was out of warranty. The vehicle was not repaired. The approximate failure mileage was 43,000.