2020 Mercedes-Benz C300 Engine Problems
- Complaints
- 8about this part
- Share
- 24%of 33 total for the year
- Median mileage
- 77,500miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 8 complaints about the engine of the 2020 Mercedes-Benz C300, 24% of the 33 complaints for this model year. Where a mileage was given, the median is 77,500 miles.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“My 2016 C300 (in-line 4 turbo, petrol with 241hp) at 55k miles had 1st cylinder cracked while driving on highway, and my car is out of warranty. I talked to my dealership and the corporate separately. The dealership would cover the cost of the parts whether the engine needs replacement or not, as I bought my car there new and have been using them through prepaid maintenance. I decided to fix the car and pay them pre-arranged labor. …”
NHTSA complaint #11382939, filed 2020-12, 55,000 miles“I am reporting a catastrophic repeat engine failure on my 2020 Mercedes-Benz C300. On October 9, 2025, with 26,589 miles, the vehicle suffered a Cylinder 2 failure (exhaust valves), causing a dangerous loss of power in traffic. I paid $4,100.43 for a $10,000 plus cylinder head replacement at an authorized dealer (Mercedes-Benz of Atlanta South) on November 13, 2025. Following the repair, the vehicle continued to exhibit multiple 'Check Engine Oil Level' warnings. On February 4, 2026—less than 90 days after the major repair—the engine suffered a total catastrophic failure. …”
NHTSA complaint #11718583, filed 2026-02“My wife was driving our 2020 Mercedes Benz C300 coupe near our house and the engine light came on. Then the car could not be driven over the speed of 30 miles per hour. Then it stopped and had to be towed. Fortunately, she was able to avoid being hit by other vehicles.The car only has 25219 miles. It was towed to a mechanic who performed a diagnostic test which provided a series of codes regarding the malfunction. Three codes were related to the CAMTRONIC camshaft system and its Solenoid ( Codes: P003C-53; P34AE-00; P34AD-09). Camshaft position actuators Failure codes: P34AD; P34AE. …”
NHTSA complaint #11589214, filed 2024-05“The contact owns a 2020 Mercedes-Benz C300. The contact stated that while at a stop, the vehicle failed to accelerate as intended. There was no warning light illuminated. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 100,000.”
NHTSA complaint #11731613, filed 2026-04, 100,000 miles“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. …”
NHTSA complaint #11733212, filed 2026-04Related service bulletins
- 11035238Jul 24, 2026Mercedes-Benz AG (“MBAG”), the manufacturer of Mercedes-Benz, has determined that on certain MY 2019-2021 C-Class, G-Class, GLC, GT, S-Class (205, 463, 253, 190 & 222 platforms)…
- 11034064Jun 19, 2026Dear Mercedes-Benz USA Dealers, The part numbers listed in the chart below should no longer be installed, and any existing stock must be returned to your facing PDC. The deadline…
- 11030302Mar 27, 2026Complaint -Check engine light illuminated. -Engine runs rough. -Poor shifting or jerking when accelerating. -Fault codes stored related to mixture formation, injector quantity…
- 11028807Feb 14, 2026Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the engine control unit software does not correspond to current…
- 11028267Feb 2, 2026Complaint -Check engine light illuminated. -Engine runs rough. -Poor shifting or jerking when accelerating. -Fault codes stored related to mixture formation, injector quantity…
- 11028003Jan 23, 2026Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA…
- 11027580Jan 10, 2026In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC is extending the…
- 11008712Oct 4, 2024Complaint Check engine light on. One of the below fault codes is current in the engine control module (N3/10). P04DB29, P04DB31, P04DB79 Cause Open circuit or high resistance to…
- 11008056Sep 16, 2024Complaint Check engine light on. Fault code P207273 - "Throttle actuator valve is blocked due to ice" stored. Engine may crank and not start. Fault code P210185 may also be…
- 11005314Jul 20, 2024Complaint Yellow Coolant warning comes on in cluster Fault codes below are current or stored in MED41 P0A0500- The actuation of the circulation pump for the low-temperature…
Engine: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2024 | 2 | 18% |
| 2023 | 2 | 9% |
| 2022 | 2 | 8% |
| 2021 | 8 | 57% |
| 2020 | 8 | 24% |
| 2019 | 17 | 25% |
| 2018 | 34 | 34% |
| 2017 | 77 | 36% |
| 2016 | 94 | 32% |
| 2015 | 127 | 33% |
| 2014 | 2 | 2% |
| 2013 | 8 | 3% |
| 2012 | 5 | 2% |
| 2011 | 10 | 2% |
| 2010 | 13 | 3% |
| 2009 | 16 | 3% |
| 2008 | 31 | 5% |
Other parts of the 2020 Mercedes-Benz C300
5 complaintsBody and structure
4 complaintsElectrical system
3 complaintsForward collision avoidance
3 complaintsFuel system
3 complaintsTransmission and drivetrain
3 complaintsVisibility (wipers, defrost, mirrors)
3 complaintsAir bags
2 complaintsBack-over prevention (rear camera)
2 complaintsLatches, locks and linkages
2 complaintsSteering
2 complaintsTires
2 complaints
← All problems reported for the 2020 Mercedes-Benz C300
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 31, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology