Some GMC Terrain owners report experiencing excessive motor oil consumption, particularly in first-generation models with the 2.4-liter 4-cylinder engine from 2010 to 2015, losing more than 1 quart between oil changes. This issue is often attributed to a defective piston design in the 2.4L engines. Additionally, some owners find that the check engine light frequently illuminates, which can indicate various engine issues; if this warning is accompanied by a low engine oil light, it is critical to stop the engine immediately and top up the oil. Failure to address excessive oil consumption can lead to catalytic converter problems, as oil contamination may affect emissions and overall vehicle performance. Therefore, it is essential for owners to investigate and resolve the root cause of oil consumption promptly to avoid costly repairs and potential engine damage.

Some GMC Terrain owners report experiencing recurring malfunctions with the driver's power seat, often attributed to a broken yellow wire in the wire harness. This issue can lead to various alarming symptoms, including unusual smells inside the vehicle, smoke emanating from the wiper arms and vents, and even wipers detaching due to a malfunctioning wiper motor. To mitigate these problems, drivers are advised to inspect the wiring at the switches and the controller for faults. Additionally, a thorough examination of the power seat system is crucial to identify and repair the broken yellow wire. Regular maintenance and prompt repairs are essential to ensure a smooth driving experience and to prevent further complications with the power seat functionality in the GMC Terrain.