Two problems related to engine knocking noise have been reported for the 2012 GMC Terrain. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 GMC Terrain based on all problems reported for the 2012 Terrain.
Vehicle was jerking at a red light with foot firmly on the brake. This happened at the base of a hill on a city street. I wasn't sure if the car would lurch into oncoming traffic. As it started driving again, it began to make a rattling and knocking noise. Car then dropped a huge amount of oil on concrete. It lost power in lower speed. Luckily I was able to limp home with the car. Had to have it towed to dealership as it wasn't drivable.
The contact owns a 2012 GMC Terrain. While driving various speeds, the vehicle stalled without warning. The vehicle was brought to the dealer for diagnostic testing, but the details could not be provided. The vehicle was repaired; however, the failure recurred. While driving at various speeds, the vehicle began to jerk and hesitate and a loud abnormal knocking noise was heard. The vehicle was taken to the dealer where it was diagnosed that the vehicle was in working condition. The contact stated that the engine failed shortly after, making the vehicle inoperable. The manufacturer was made aware of the failures. The failure mileage was 135,000.