What breaks most · 2017 to 2026 model years
Mercedes-Benz C 300 problems by year
Owners have filed 490 safety complaints with NHTSA about the Mercedes-Benz C 300 across model years 2017 to 2026. One year stands out: 2017 for engine complaints. The quietest years are 2024, 2021 and 2023.
- Years to check closely: 2017
- Fewest complaints: 2024, 2021, 2023
- Complaints on file
- 4902017 to 2026, all trims
- Worst year
- 2017216 complaints
- Crashes reported
- 273 fires · 26 injuries · 0 deaths
- Typical failure mileage
- 29kMedian where owners gave mileage
- Recall campaigns
- 90Across the years shown
Complaints by model year
Raw filings with NHTSA, not adjusted for how many were sold.
| Model year | Complaints | Crashes | Recalls | Most-reported component |
|---|---|---|---|---|
| 216 | 10 | 15 | Engine (77) | |
| 98 | 4 | 18 | Engine (34) | |
| 66 | 3 | 17 | Engine (15) | |
| 33 | 5 | 9 | Engine (8) | |
| 14 | 0 | 7 | Engine (8) | |
| 25 | 1 | 9 | Electrical system (7) | |
| 22 | 2 | 9 | Forward collision system (10) | |
| 11 | 2 | 3 | Electrical system (4) | |
| 4 | 0 | 2 | Backup camera and sensors (2) | |
| 1 | 0 | 1 | Speed control and throttle (1) |
What fails on the 2017 Mercedes-Benz C 300
| Component | Share of complaints | Filings | Crashes | Parts for this job |
|---|---|---|---|---|
| EngineEngine gaskets and seals | 36% |
77 | 0 | Shop all engine parts, not filtered to this vehicle |
| Unknown or other | 16% |
34 | 2 | — |
| Electrical systemAlternators, starters and ignition | 14% |
31 | 1 | Shop all electrical system parts, not filtered to this vehicle |
| Fuel systemFuel pumps and injectors | 14% |
30 | 0 | Shop all fuel system parts, not filtered to this vehicle |
| Body and structureDoors, latches and body hardware | 11% |
24 | 2 | Shop all body and structure parts, not filtered to this vehicle |
| Seat belts | 10% |
21 | 2 | Check recalls for seat belts on NHTSA.gov |
| Air bags | 7% |
15 | 6 | Check recalls for air bags on NHTSA.gov |
| SteeringPower steering pumps, racks and hoses | 6% |
13 | 2 | Shop all steering parts, not filtered to this vehicle |
One complaint can name more than one component, so shares add to more than 100%. "Unknown or other" is NHTSA's uncategorized bucket and is shown but never ranked.
In owners' words
Complaint narratives as filed with NHTSA, trimmed for length.
-
2017 Mercedes c300 the switchover valve in the diagnostic module of the evaporative emission control system is jammed open. This issue was called for recall for models 2018 or later, but 2017 was not part of it.
How to read this page
Every figure comes from the National Highway Traffic Safety Administration's public complaint database, which holds every safety-related defect complaint filed by owners since 1995. We refresh it monthly and count each complaint once per component it names. Data through September 6, 2026.
NHTSA only accepts safety-related complaints. Rattles, paint, infotainment bugs and other annoyances are under-reported here, so this page is a map of what fails in ways owners consider dangerous, not a full reliability score.
Counts are raw. Use the year-over-year shape and the component mix, not the absolute numbers. Where a component maps to parts we stock, the row links to that category filtered to the year you are viewing. Air bag and seat belt complaints link to the recall checker instead, because those repairs are almost always covered.
Common questions
Which Mercedes-Benz C 300 years have the most problems?
By NHTSA complaint volume, 2017 carries the most filings on the Mercedes-Benz C 300. The 2017 alone has 216 complaints, led by engine.
What is the most common Mercedes-Benz C 300 problem?
On the 2017 model year, the most-reported component is engine with 77 complaints. The table above lists the top components for every year.
At what mileage do Mercedes-Benz C 300 problems start?
The median mileage at failure across all Mercedes-Benz C 300 complaints that include mileage is about 29,000 miles. Older model years skew higher; the per-year figure is in the "at a glance" card.
Are these complaints verified?
No. NHTSA publishes complaints as submitted and does not investigate individual filings. Patterns across hundreds of complaints are meaningful; a single one is not.