2020 Mercedes-Benz C 300 problems and owner complaints
Explore the records behind recurring owner reports.
Key facts
33 owner complaints analyzed
9 distinct recall campaigns
28,722 mi median reported failure mileage
Scope: 2020 model year. Data snapshot: . 11 complaints include usable failure mileage.
Most common problems
Engine is the most frequently named component, appearing in 8 of 33 complaints (24.2%). A complaint can name multiple components.
| Topic | Matching reports | Share of complaints |
|---|---|---|
| Engine operation | 4 | 12.1% |
| Braking behavior | 3 | 9.1% |
| Steering behavior | 3 | 9.1% |
| Electrical and battery issues | 2 | 6.1% |
| Fuel system concerns | 1 | 3.0% |
Topic matches use published keyword rules. They describe mentions, including negations or comparisons, and do not confirm a diagnosis. Read the matching rules.
Component breakdown
Number of unique complaints naming each component. Top eight shown.
| Category | Count |
|---|---|
| Engine | 8 |
| Unknown Or Other | 5 |
| Electrical System | 3 |
| Fuel/Propulsion System | 3 |
| Power Train | 3 |
| Air Bags | 2 |
| Back Over Prevention | 2 |
| Forward Collision Avoidance: Automatic Emergency Braking | 2 |
Engine: 8; Unknown Or Other: 5; Electrical System: 3; Fuel/Propulsion System: 3; Power Train: 3; Air Bags: 2; Back Over Prevention: 2; Forward Collision Avoidance: Automatic Emergency Braking: 2
Reported problems by failure mileage
Complaint counts in mileage bands. These are not failure rates per vehicle or mile.
| Category | Count |
|---|---|
| Under 25,000 | 5 |
| 25,000 to 49,999 | 2 |
| 50,000 to 74,999 | 1 |
| 75,000 to 99,999 | 1 |
| 100,000 to 149,999 | 2 |
| 150,000 and above | 0 |
Under 25,000: 5; 25,000 to 49,999: 2; 50,000 to 74,999: 1; 75,000 to 99,999: 1; 100,000 to 149,999: 2; 150,000 and above: 0
Under 25,000 miles has the most reports with usable mileage (5). 22 complaints have missing, zero or invalid mileage.
Complaints over time
Year the complaint was filed, not the vehicle model year or incident year. The snapshot year is partial.
| Category | Count |
|---|---|
| 2020 | 4 |
| 2021 | 5 |
| 2022 | 5 |
| 2023 | 1 |
| 2024 | 4 |
| 2025 | 7 |
| 2026 | 7 |
2020: 4; 2021: 5; 2022: 5; 2023: 1; 2024: 4; 2025: 7; 2026: 7
Pattern summary
Engine leads the component reports. Engine operation appears in 4 complaint narratives. Braking behavior appears in 3 complaint narratives. Steering behavior appears in 3 complaint narratives. Use these patterns to inspect individual reports and prepare questions for a mechanic.
Calculated from recorded counts. An AI narrative has not been published for this selection.
Complaint evidence
Examples provide context, not a representative sample or a verified diagnosis.
Owner report 11654115 · 2025-04-11 (April 11, 2025)
I own a 2020 Mercedes-Benz C300, and the check engine light recently came on. The vehicle has only around 27,000 miles and has been regularly maintained at an authorized dealership. Diagnostic testing revealed fault code P06DA00, indicating an electrical failure or open circuit in the engine oil pump control valve. The dealership confirmed that the valve could not actuate and provided a repair estimate exceeding $7,000 due to the labor-intensive nature of the repair. This issue occurred shortly after the factory warranty expired. The sudden l…
Owner-reported narrative. Look up ODI 11654115 at NHTSA ↗
Owner report 11695702 · 2025-10-26 (October 26, 2025)
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 …
Owner-reported narrative. Look up ODI 11695702 at NHTSA ↗
Owner report 11452817 · 2022-02-18 (February 18, 2022)
Automatic emergency braking system & forward collision warning. I experienced a medical emergency and blacked out, hitting 3 cars. The incident happened the morning of Dec. 31, 2021 and my car still has not been evaluated by Mercedes. I was taken to the ER and spent 3 days in the hospital.
Owner-reported narrative. Look up ODI 11452817 at NHTSA ↗
Owner report 11490902 · 2022-10-25 (October 25, 2022)
The component that failed was the fuel injector and spark plug. A few months prior to this incident, I was making a left hand turn, when the accelerator completely gave out. I was making the left on a blinking yellow arrow, luckily the on coming car was not coming at me fast or I would've been in an accident due to the accelerator failing. I had to pull over, turn the car off and then back on to reset it. I was told by the dealership service center that they could not find anything and that there have been no complaints or recalls. After about …
Owner-reported narrative. Look up ODI 11490902 at NHTSA ↗
Owner report 11423100 · 2021-07-01 (July 1, 2021)
While driving on the turnpike without warning my steering locked and I lost control of my car.
Owner-reported narrative. Look up ODI 11423100 at NHTSA ↗
Owner report 11667088 · 2025-06-16 (June 16, 2025)
Over the past month, my 2020 Mercedes-Benz C300 has been experiencing unexpected and increasingly concerning issues with the steering. These problems began suddenly and without any prior warning signs. Initially, the steering has been making grinding sounds more usual, particularly at lower speeds and when making tight turns. Over the following weeks, the issue became more pronounced, with occasional instances of the steering wheel resisting movement or feeling delayed in its response. At times, it feels as if the power steering system is inter…
Owner-reported narrative. Look up ODI 11667088 at NHTSA ↗
Owner report 11733212 · 2026-04-23 (April 23, 2026)
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…
Owner-reported narrative. Look up ODI 11733212 at NHTSA ↗