2020 GMC Terrain engine problems
55 owner complaints filed with NHTSA name the engine on the 2020 GMC Terrain — 30% of all complaints for this model year.
What owners report
“Vacuum pump failure causing sudden and unexpected hard brake pedal and loss of braking coming off the highway. Ended up catastrophic engine failure. This is the SECOND incident with this vehicle of the exact same problem. GMC refuses to address this issue and continues to risk the lives of their…”
filed Jul 23, 2026
“During my daily commute to work on the interstate the service break assist message came on my dash and when attempting to break the pedal was very hard, to the point where I had to push extremely hard and quickly realized I had to brake much much soon than normal to prevent hitting other vehicles…”
filed Jun 8, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Engine problems in other Terrain years
| Year | Reports | Share |
|---|---|---|
| 2026 Terrain | 1 | 4% |
| 2024 Terrain | 11 | 23% |
| 2023 Terrain | 13 | 36% |
| 2022 Terrain | 10 | 21% |
| 2021 Terrain | 8 | 24% |
| 2019 Terrain | 63 | 36% |
| 2018 Terrain | 51 | 24% |
| 2017 Terrain | 77 | 58% |
| 2016 Terrain | 45 | 30% |
| 2015 Terrain | 80 | 27% |
| 2014 Terrain | 123 | 42% |
| 2013 Terrain | 197 | 54% |
Other reported problem areas on the 2020 GMC Terrain
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.