Mercedes-Benz C300 jerking problems

Filed Aug 16, 2026 · Transmission · CA

Shifting gears when stopped and the car lunged forward while I was stopped at a red light. I almost hit the car in front of me at the red light. Very rough gear changes and changing out of the correct gear to the wrong one and then back into another one. Severe speed changes - jerking the car back or it lunges forward, while driving results in loss of reasonable control of the vehicle and inability to to shift correctly out of traffic. Mercedes benz has a technical service bulletin on this problem and is aware that the 9G-Tronic - internally designated as the 725 transmission (fault code P07B700) is defective and known to experience sudden pressure sensor failures or valve body faults within the transmission control unit which prevents the car from shifting gears corrected or forces limp mode. The repair is a minimum of $5,200. MBZ has known this is a defect and wide spread issue but unwilling to contribute to the repair or recall or respond to my letters and the inquiries of other vehicle owners I have spoken to that have the same issues. It is a catastrophic mechanical failure from a sensor they know is bad and is occurring shortly after warranties are expiring. It is putting all of our lives and the lives of others at risk of an accident due to the failure of their part. Thank you for your consideration.

Filed May 19, 2026 · Engine · GA

Upon starting engine while parked the engine vibrated roughly then stopped. Engine light and coolant light illuminated but shut off. Vehicle proceeded as normal, however, as I proceeded for the highway about 1 - 1/2 blocks and approximately 1,200 feet before approaching highway the vehicle 1200 abruptly lost acceleration; engine light and coolant light illuminated again, then engine abruptly shut down in the middle of the road causing a severe safety hazard. Putting myself and others at risk. There were no symptoms of the problems prior to the failure. Coolant leakage; sluggish engine/acceleration; jerking acceleration; coolant light illumination steady.

Filed Jan 8, 2026 · FL

The car jerks so hard at times randomly that it feels like I got rear ended and it is completely unsafe. It also does small jerks at times. It's happened driving 70 mph down a highway, making a right turn accelerating slowly. Going slow down the street at 35, at a red light completely stopped or stop sign. There's no rhyme or reason to it. I've taken it to Mercedes five or six times now with the same issue and they have not been able to duplicate the problem. It's currently at Jacksonville Mercedes dealership where I bought it with the foreman. He is with my permission driving it back and forth to work because I said I do not want the car back until they can duplicate the problem and fix it or recall it or give me a new one or give me my money back. One of the instances that jerked so hard that it hurt my back. None of the sensors go off when it's plugged in while they're trying to locate a problem it only happens when it's being driven and again there's no rhyme or reason to when it happens. It does happen pretty regularly at least 10-12 times hard over the last year and the little ones happen more frequently at least 20 to 30 over the last year the last time being when I drove it on 1/5/26. Miles have been from 200 to 9100. It been happening for a year now. Mercedes Clearwater and Mercedes Jacksonville will have all of the files from the five or six times I've brought it in. I also attempted to get a lemon law request through Mercedes executive services in March or April which they denied because they couldn't duplicate the problem, but there was never a serious attempt to duplicate it by Mercedes until now that it's at the Jacksonville location where I purchased it from. The Foreman and GM there are taking it more seriously and the foreman again is driving it back and forth to work in hopes of duplicating the problem.

Filed Jul 18, 2025 · Brakes, Driver assistance · NJ

On 4 different occasions car brake assist activated causing car to come to an immediate stop and jerk. At stop light as I started to accelerate a left turn car came to an immediate stop almost causing the car behind hit rear end. Brake assist light activated. This happened twice. And twice when in reverse backing out of a parking space and backing into driveway. Dealership notified look at my car and stated they did not see anything wrong. 4th incident happened within 30 minutes after leaving Wilmington Mercedes Benz.

Filed Oct 6, 2023 · VA

I started hearing noises about a week ago while driving. Last night while driving home in the evening traffic, I braked and car violently jerked and veered to the right almost hitting the car in the front. I took the car to a shop this morning and they found that the rear subframe had collapsed due to rust and advised the car was extremely dangerous to drive.

Filed Mar 12, 2023 · Suspension · SC

Car was garage kept and in mint condition, yet the rear subframe has completely rusted through and while breaking the car lurches to the right. Also the breaking performance is noticeably impaired. There was no signs of this failure as the car still looks new, only way of knowing was the near crash while driving and trying to stop.

Filed Oct 19, 2022 · Suspension · NY

Rear Sub frame faiIure / rusted and rotted On this site alone there are complaints listed under 3 different heading Structure (30) / SUSPENSION (38) / UNKNOWN OR OTHER (20) all related to the rear sub frame. not to mention 100's on the web. I nearly died when I hit the brakes the car lurched to the left at highway speed. My mechanic told me that the rear Subframe was rotted and the rear control arm is no longer connected to the sub frame He insisted that the car is UNSAFE to drive. He was very surprised as the car only has 70,000 miles on it and in good shape with no rust anywhere else on the car. I did a quick search of the issue on the web and immediately found that MB has had this issue across the world in various models manufactured in 2011-2014. Presently, there are recalls in Germany and Canada for this issue. I contacted my MB Service department and was informed that no recall for this issue exists in the US and they would not cover the costs to repair. The repair could cost between $5k to $7k They told me that I would need to contact MB North America Customer Service. I find it amazing that MB Service, Dealers and North America HQ are all aware of this issue but the Company will not issue a recall or stand behind their product. This not some minor defect. When a major structural component of the car is compromised the lives of vehicle occupants and others on the road are at risk of death due to a major accident. The vehicle is now undriveable and will cost several thousands of dollars to repair. MB is fully aware of this issue and refuses to do anything about it. the federal safety agency needs to address this issue and make the Manufacturer stand behind their Quality pledge which as a consumer you are paying for when purchasing what you expect to be exceptional German engineering and what you are given is a a product with a known defect that will not be addressed.

Filed Sep 8, 2022 · Suspension · 110,000 miles · IN

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.

Filed Jul 27, 2022 · Suspension · NJ

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

Filed Jul 22, 2022 · Electrical, Fuel system · MD · crash

I was moving my car from one parking space to another space in front of my house. As I was pulling into the new space, I stopped to check the position of my car. As I lifted my foot off the brake, the car unexpectedly started to lurch forward. When I released the brake pedal, the car suddenly accelerated and proceeded to jump the curb and run into the front of my house. Luckily, no one was injured. There was some damage to the exterior of my house. I have reported this issue to the car manufacturer, Mercedes Benz. In response, they have opened a case to research it further.