2015 GMC Terrain: sudden loss of power

Filed Jul 22, 2026 · Engine · IL

I am submitting this complaint regarding the engine timing chain failure in my 2015 GMC Terrain because I believe it presents a serious safety hazard. Before the failure, the vehicle began experiencing intermittent symptoms, including engine jerking, shaking, rough operation, abnormal engine noises, and an intermittent check engine light. While driving on the highway, the engine timing chain failed, causing the vehicle to suddenly lose power. I was traveling at highway speed and had to safely maneuver the vehicle out of traffic. The unexpected loss of power placed me and other motorists at risk of a collision because I could no longer safely maintain the flow of traffic. The vehicle was towed to an independent repair facility, where the engine was diagnosed with a timing chain failure. I was informed that the engine had sustained significant damage and required replacement. After purchasing and installing a replacement engine, that engine also began exhibiting timing chain-related symptoms immediately after installation, including abnormal rattling noises and unstable engine operation, resulting in additional repairs and the vehicle remaining unsafe to drive. I am concerned that timing chain failures in this model can occur without sufficient warning and can cause a sudden loss of engine power while the vehicle is being driven. A sudden engine failure at highway speeds creates a significant risk of a crash, injury, or death. I am requesting that this issue be investigated to determine whether it represents a safety-related defect affecting other 2015 GMC Terrain vehicles.

Filed Mar 12, 2024 · Fuel system · 130,000 miles · IN

The contact owns a 2015 GMC Terrain. The contact stated that while driving at an undisclosed speed and coming to a complete stop, the accelerator pedal was released, and the vehicle sputtered. The check engine warning light was illuminated. The message "Reduced Engine Power" was displayed. Additionally, the contact stated that the vehicle would shut off while idling unless the accelerator pedal was intermittently depressed. The contact also stated that the vehicle had failed to respond while depressing the accelerator pedal. The vehicle was taken to Firestone on several occasions, and the high-pressure fuel pump (HPFP) was replaced 3 times; however, the failure persisted. The vehicle was not repaired. The dealer was not notified of the failure. The manufacturer was notified of the failure and referred the contact to the federal safety agency Hotline for assistance. The failure mileage was approximately 130,000.

Filed May 24, 2023 · Electrical, Engine · MI

Engine lost power suddenly while driving. No warning. Fuel pressure slowed to where vehicle no longer moved forward. Again. No warning. Timing chain slipped TWICE and destroyed engine without warning. “Engine power lost” appeared on dash from driving without warning or incident. Excessive oil consumption without warning. Smoking engine even though had regular oil changes. Engine had been inspected by dealership and allegedly had no issues. Car never smoked but did after second time of timing chain slipping/breaking. This issue has happened repeatedly to many drivers who own these vehicles. Had a difficult time stopping after engine and total power failure without warning.

Filed Dec 25, 2022 · Engine · WI

Stopped at Kwik Trip to get coffee before work one morning. Restarted Terrain and while leaving the SUV lost power and went into limp mode in heavy traffic. Car was towed to repair facility. Diagnosed as timing chain and guides failed resulting in major engine damage. Bill was $4302.85. Vehicle had 87397 miles on it.

Filed Nov 18, 2022 · Engine, Transmission · NH

The engine is burning oil at a rate of about a quart every 2k miles. The check engine light came on recently and very shortly after a reduced power warning came on and made the vehicle difficult to drive. Which was not safe on a major road. It had to be towed to my mechanic and he mentioned to me that the engines in this vehicle are known to be problems. The pistons have an issue that burns oil in excess he said. I looked this up and found a class action settlement was just awarded to people in 3 states. However not mine.

Filed Feb 24, 2017 · Electrical, Lights · 126,000 miles · WA

Tl* the contact owns a 2015 gmc terrain. While driving at normal speeds, the headlights lost power. The dealer was unable to duplicate the failure. The vehicle was not repaired. The failure mileage was 126,000.

Filed Nov 24, 2015 · Transmission · FL

2015 gmc terrain. Consumer writes in regards to sudden loss of engine power, accelerator pedal and throttle failures. *smd the consumer stated when she tried to accelerate, the vehicle barely moved. The consumer turned off the vehicle and re-started it, with the same results. The engine would just idle as if the accelerator pedal was disconnected.