Transmission complaints by model year
| Year | Complaints | Share of year's complaints | Typical mileage |
|---|---|---|---|
| 2024 | 1 | 7% | — |
| 2023 | 1 | 4% | — |
| 2021 | 2 | 13% | — |
| 2020 | 3 | 9% | — |
| 2019 | 6 | 9% | 36,000 miles |
| 2018 | 2 | 2% | 62,000 miles |
| 2017 | 12 | 6% | 36,000 miles |
| 2016 | 18 | 6% | 4,000 miles |
| 2015 | 20 | 5% | 28,000 miles |
| 2014 | 1 | 1% | 0 miles |
| 2013 | 3 | 1% | 99,000 miles |
| 2012 | 5 | 2% | 88,000 miles |
| 2011 | 10 | 2% | 69,000 miles |
| 2010 | 15 | 3% | 52,000 miles |
| 2009 | 5 | 1% | 41,000 miles |
| 2008 | 16 | 2% | 66,000 miles |
Which parts fail
Components named in complaints (automatic and manual transmissions, CVT, axles, driveshaft, 4WD/AWD).
Mileage when the problem started
What owners report
I purchased this 2020 Mercedes-Benz C300 only two months ago and have driven it less than 3,000 miles. The Carfax report shows consistent maintenance and regular service history by prior owners. While driving, the check engine light came on and the vehicle began shaking and running roughly. Diagnostics by Peachtree Imports (10/03/2025) and later by Mercedes-Benz of Atlanta South confirmed Cylinder #2 failure on the M264 2.0L engine at only 26,589 miles. The dealer's report states: "Cylinder #2 mixture formation out of spec. Fault occurred due to worn exhaust valve seat. Cylinder head replacement required." Estimated repair cost: $10,470.66. This causes misfire, loss of power, and unsafe drivability. The failure matches Mercedes-Benz Technical Service Bulletin LI01.30-P-072328 (2021), which documents valve-seat leakage in M264 engines requiring head replacement. …
Vehicle has ongoing and recurring electrical and engine-related defects that affect safe operation. The primary systems involved are the electrical system, engine ignition system, and powertrain. The vehicle is available for inspection upon request. Prior service records show issues beginning in 2020 involving repeated electronic system failures requiring multiple repairs and component replacements. Since purchasing the vehicle in April 2023, the vehicle has developed more serious failures, including: - September 2024: Check engine light with loss of power and inability to exceed safe driving speeds - October 2024: Engine misfiring due to ignition coil failure requiring replacement of ignition components - September 2025: Additional ignition coil electrical fault (code P0353) The problem has been reproduced and confirmed through dealership service inspections and diagnostic reports. …
The contact owns a 2019 Mercedes-Benz C 300. The contact stated that while driving 65 MPH, the vehicle inadvertently lost motive power, and was unable to accelerate above 25 MPH. The check engine warning light was illuminated. The vehicle was taken to the dealer, who determined that the PCM required a software update. The vehicle was repaired. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 36,000.
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. …
The contact owns a 2017 Mercedes-Benz C300. The contact stated that while at a stop light the vehicle stalled. There were no warning lights illuminated. The vehicle was taken to the local dealer where it was diagnosed and determined that the battery cable needed to be replaced. The vehicle was repaired but the failure recurred. The vehicle was taken back to the local dealer where it was diagnosed that an update to the powertrain software was needed, and the transmission pump needed to be replaced. The vehicle was repaired but the failure persisted. The contact called the local dealer, and it was recommended that the transmission be replaced. The vehicle was not repaired. The manufacturer was contacted. The failure mileage was approximately 80,000.
At approximately 26,500 miles of use, the check engine light came on in my Mercedes Benz C300. I brought the vehicle to the dealership and they informed me that the diagnosis was a crankcase vent valve malfunction. The MB fault code is P52E71. After paying Mercedes to fix the issue, I found forums on the internet where many other MB owners reported the same issue at around the same mileage. Being that this seems to be a common malfunction with the C300, I believe that it should be considered as a recall issue. I don't know what could have happened if I didn't service the vehicle, but any engine issue is dangerous while a vehicle is in motion.
My C300 MBZ, 2016 is experiencing the same symptoms as indicated in a recall, but my vehicle is not included in that recall. Camshaft: GENERAL REPAIR A cam is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion or vice versa. Cams act as a vital component to your automobile's engine. A camshaft is a shaft to which a cam is fastened or of which a cam forms an integral part. Camshafts provide power to the cams which are vital for basic engine operation. The cost of fixing this approximately $10,000 per Mercerdes dealer and estimate from Keyes Mercerdes. The Brief: Mercedes-Benz issued a recall for some model cars tied to a faulty drive shaft.T he problem not only can cause vehicles to lose power but may elevate crash risk, according to the National Traffic Safety Administration. …
I bought the car with 51k miles . Engine failed at 71k miles , due to piston #1 cracking . Almost caused me to get rear ended on a busy street . I went to the dealership and they charged me $10250 to replace the engine with a remanned long block and they offered a 2 year warranty. 9 months, only 19k miles on "new motor" the "new" engine fails again ... same reason piston # 1 cracked failed suddenly on the highway and I had to push the car to safety to the emergency lane while cars where coming.. I went back to dealer demanding a replacement and told them this is a common occurrence and they refused to help me . I called corporate. They refused to help me saying I would have to purchase an engine for the second time out of pocket when it only lasted 9 months. This is a big fault in the m274 engine ... …
Frequently asked questions
Which Mercedes-Benz C300 years have transmission problems?
By NHTSA complaints, the 2015 (20), 2016 (18), 2008 (16), 2010 (15) and 2017 (12) model years. Transmission complaints make up 5% of all complaints for the 2015.
Is there a recall for Mercedes-Benz C300 transmission problems?
No. NHTSA lists no transmission & drivetrain recall for any Mercedes-Benz C300 model year. A widespread problem may still be covered by an extended warranty or a manufacturer service bulletin, so ask a dealer.
At what mileage do Mercedes-Benz C300 transmission problems start?
Across all years, half of the complaints with a recorded mileage happened before about 53,000 miles; 45% happened before 50,000 miles.
What part fails most often?
Owners most often name the automatic transmission (2 mentions).
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.