2017 Mercedes-Benz C 300 engine problems
77 owner complaints filed with NHTSA name the engine on the 2017 Mercedes-Benz C 300 — 36% of all complaints for this model year.
What owners report
“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.”
filed Jul 27, 2026
“The contact owns a 2017 Mercedes-Benz C300. While driving at approximately 15 mph, the contact observed smoke emanating from under the hood. The vehicle was driven to her work location and parked. Upon exiting the vehicle and opening the hood, she observed orange flames coming from the engine…”
filed May 15, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Related service bulletins
Dear 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 for all dealer returns is no later than…
PSL-NCU Return Parts 6/19 · Other · issued Jun 19, 2026
Engine problems in other C 300 years
| Year | Reports | Share |
|---|---|---|
| 2023 C 300 | 2 | 9% |
| 2022 C 300 | 2 | 8% |
| 2020 C 300 | 8 | 24% |
| 2019 C 300 | 16 | 24% |
| 2018 C 300 | 34 | 34% |
Other reported problem areas on the 2017 Mercedes-Benz C 300
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.