2018 Mercedes-Benz GLC 300 engine problems
28 owner complaints filed with NHTSA name the engine on the 2018 Mercedes-Benz GLC 300 — 32% of all complaints for this model year.
What owners report
“Error code P052E71 on a 2018 Mercedes-Benz GLC 300 4MATIC means the Positive Crankcase Ventilation (PCV) Regulator Valve Performance has a malfunction, specifically that the partial-load ventilation valve actuator is blocked. By research, i found that this is a very common problem on those engines…”
filed Jul 30, 2026
“Component Failure: The vehicle is equipped with the M274 2.0L turbocharged engine, which suffered a major internal mechanical defect. An authorized Mercedes-Benz dealership diagnosed the vehicle at 79,504 miles with a malfunction in the crankcase ventilation system alongside severe internal…”
filed Jun 3, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Engine problems in other GLC 300 years
| Year | Reports | Share |
|---|---|---|
| 2024 GLC 300 | 7 | 33% |
| 2023 GLC 300 | 15 | 27% |
| 2022 GLC 300 | 9 | 16% |
| 2021 GLC 300 | 29 | 48% |
| 2020 GLC 300 | 20 | 30% |
| 2019 GLC 300 | 11 | 24% |
Other reported problem areas on the 2018 Mercedes-Benz GLC 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.