Model years Mercedes-Benz C-Class
2015 Mercedes-Benz C-Class
Complaints about this year name valve far more often than the model's other years — 14% of them, about 35× the usual rate of 0.4%.
NHTSA opened a defect investigation into this model year.
| Complaints filed | 878 |
|---|---|
| Median for this model | 254 |
| Involving a crash | 22 |
| Involving a fire | 2 |
| Recalls | 0 |
| NHTSA crash rating | 4/5 |
| EPA combined | 25 mpg |
What the complaints were about
- valve — 20% of this year's complaints, against 2% across the model's other years (9.9×). Owners wrote it as: valve, crankcase, ventilation, crankcase ventilation.
- sunroof — 18.5% of this year's complaints, against 6.4% across the model's other years (2.9×). Owners wrote it as: sunroof, panoramic, glass, panoramic sunroof.
- code — 9.3% of this year's complaints, against 2.1% across the model's other years (4.4×).
Words owners used for the same problem are counted together, so a fault written four different ways is measured once. Grouped by which complaints they appear in, not by a list anyone wrote in advance.
Also unusual this year
- crankcase — 13% of complaints, 32× usual
- rear subframe — 9% of complaints, 23× usual
- roof — 9% of complaints, 22× usual
What owners wrote
Known/ common issue with the positive crankcase ventilation regularly valve on my 2015 c300.
Crankcase ventilation valve malfunctioning Second time with car. Creating trapped exhaust in crankcase.
Verbatim from NHTSA complaint filings, with identifying details removed.
How this was worked out
Every year of the Mercedes-Benz C-Class was compared against its own history rather than against other cars, which removes popularity and age from the answer — a common car draws more complaints at equal reliability, and an older one has had longer to accumulate them. A year is flagged when it drew at least 2.5× this model's median and at least 50 complaints.
This is a fault record, not a review. Nobody files a federal complaint to say the car was fine, so it shows what tends to go wrong — not whether owners liked it, and not whether it is a good car.
Source: NHTSA complaints, recalls and investigations, retrieved . Look this vehicle up directly on NHTSA's site to check anything here.
Own a 2015 Mercedes-Benz C-Class? What happened to yours?
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