NHTSA owner reports · September 18, 2026 snapshot.
Engine complaints
9 reportsClear category filterMileage unknown · Sep 11, 2026
Engine
Vehicle Information:Year/Make/Model: 2021 GMC TerrainEngine Type: 1.5L Turbocharged EngineCurrent Mileage: 155,000 miles [1]Description of Safety Defect:I am writing to report a severe, sudden engine and turbocharger failure on my 2021 GMC Terrain that presents an extreme, life-threatening safety hazard. While operating the ve…
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Vehicle Information:Year/Make/Model: 2021 GMC TerrainEngine Type: 1.5L Turbocharged EngineCurrent Mileage: 155,000 miles [1]Description of Safety Defect:I am writing to report a severe, sudden engine and turbocharger failure on my 2021 GMC Terrain that presents an extreme, life-threatening safety hazard. While operating the vehicle in active traffic, the engine began flashing a severe dashboard warning reading "Stop Now Danger" (accompanied by low oil pressure alerts) before suffering an immediate, catastrophic loss of all motive power. 2-This unexpected stalling leaves the driver completely stranded on active roadways without warning, drastically expanding the risk of a high-speed rear-end collision. A mechanic has inspected the vehicle and confirmed that both the engine assembly and the turbocharger require full replacement, with a repair estimate totaling $12,000. General Motors is currently facing legal actions regarding defective, camshaft-driven mechanical vacuum pumps and PCV configurations on these 2018–2022 1.5L engines defects known to fracture, send metal fragments violently into the engine top, and trigger immediate engine failure and turbocharger destruction. Despite these severe risks, GMC has refused to provide any goodwill assistance or repairs because the vehicle is outside warranty. I request that NHTSA immediately investigate the engine-destroying defects inherent to the 2018–2022 GMC Terrain line to protect consumers from catastrophic highway power failure.
NHTSA ODI #11763647
Mileage unknown · Mar 16, 2026
EngineEngine And Engine Cooling
Vehicle went into reduce engine power mode and check engine light came on. Vehicle has just over 60,000 miles. Code is telling me I need a new turbo and being quoted $1,500-$3,000. I have read so many people having the same issue with needing a new turbo just after 60,000 miles
NHTSA ODI #11724745
Mileage unknown · Mar 16, 2026
Engine
The contact owns a 2021 GMC Terrain. The contact stated that while driving at various speeds, the vehicle hesitated while depressing the accelerator pedal, with a misfire coming from the engine. During the failure, the message "Engine Power Reduced" was displayed on the instrument panel. The vehicle was taken to a local dealer, …
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The contact owns a 2021 GMC Terrain. The contact stated that while driving at various speeds, the vehicle hesitated while depressing the accelerator pedal, with a misfire coming from the engine. During the failure, the message "Engine Power Reduced" was displayed on the instrument panel. The vehicle was taken to a local dealer, and the contact was provided an estimate for a diagnostic test. The contact declined. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was unknown.
NHTSA ODI #11724576
Mileage unknown · Jan 26, 2026
EngineFuel/propulsion SystemLane Departure
The engine light came on while driving, saying “engine power reduced”. It barely accelerates, RPMs go over 5, it chugs when driving. Taken to an independent service center.
NHTSA ODI #11713477
Mileage unknown · Jan 22, 2026
Engine
around chirstmas, Was driving on the highway and the car threw a "reduced engine power" warning and went into limp mode. Check engine light came on. Car asymptomatic prior. got the code pulled and it said turbocharger under boost. The next day the check engine light went out and car was running appropriately. Took the car on the…
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around chirstmas, Was driving on the highway and the car threw a "reduced engine power" warning and went into limp mode. Check engine light came on. Car asymptomatic prior. got the code pulled and it said turbocharger under boost. The next day the check engine light went out and car was running appropriately. Took the car on the highway again and the car threw the "reduced engine power" warning and went into limp mode again in the middle of freeway traffic. It is a safety concern due to the engine going into limp mode in the middle of high speed traffic. I easily couldve caused an accident putting both myself and others in danger by the engine cutting the power in the middle of the freeway. The check engine light only comes on while going at freeway speeds. The light will then go out overnight and come back on the next time i go back on the freeway at 70-80mph speeds. I have taken it to one shop which reported an oil leak coming from the turbo both inside and outside and that it needed to be replaced. I have read several different forums of other users of the same year, make, and model experiencing the same issue. the car is only a few years old and the likelihood of a turbocharger being bad is uncommon but a major safety concern considering this happened out of nowhere with no signs or symptoms leading up to this.
NHTSA ODI #11712586
36,000 miles · Apr 24, 2025
EnginePower Train
The contact owns a 2021 GMC Terrain. The contact stated while driving at various speeds, the transmission erroneously shifted to the neutral, causing the vehicle to decelerate. After restarting the vehicle, the vehicle operated normally. During the failure, the message " Power Reduced" was displayed. The cause of the failure was…
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The contact owns a 2021 GMC Terrain. The contact stated while driving at various speeds, the transmission erroneously shifted to the neutral, causing the vehicle to decelerate. After restarting the vehicle, the vehicle operated normally. During the failure, the message " Power Reduced" was displayed. The cause of the failure was not yet determined. The local dealer was notified of the failure. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was 36,000.
NHTSA ODI #11656552
86,000 miles · Apr 4, 2025
EngineFuel System, Gasoline
The contact owns a 2021 GMC Terrain. The contact stated while driving 5 MPH, the vehicle stalled. There was no warning light illuminated. The contact stated that the failure was like GM Product Safety Recall: N222372310 (Inadequate Fuel Pump Flow). The vehicle was towed to an independent mechanic, who determined that the fuel pu…
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The contact owns a 2021 GMC Terrain. The contact stated while driving 5 MPH, the vehicle stalled. There was no warning light illuminated. The contact stated that the failure was like GM Product Safety Recall: N222372310 (Inadequate Fuel Pump Flow). The vehicle was towed to an independent mechanic, who determined that the fuel pump had malfunctioned and damaged the camshaft. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The approximate failure mileage was 86,000.
NHTSA ODI #11652800
Mileage unknown · Jan 14, 2025
Electrical SystemEngineFuel/propulsion System
I purchased the car August 2024, I have had it for 4 months and while driving down the road a large fuel tank pops up stating low fuel and the car comes to an abrupt stop.The 3x the gas tank was never low. Parking brake comes on and car doesn't not move. All lights on dash come one. It has done it 4 times and thankful each time …
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I purchased the car August 2024, I have had it for 4 months and while driving down the road a large fuel tank pops up stating low fuel and the car comes to an abrupt stop.The 3x the gas tank was never low. Parking brake comes on and car doesn't not move. All lights on dash come one. It has done it 4 times and thankful each time I was in a 30 mph zone. If I was going 55 I am sure the result would have been bad. The car last did it on December 29, 2024 and has been in the dealership for 3 weeks now and they cannot fix it. I told them 3 days into my purchase I wanted a full refund and they denied me. ?? I had that right I am still fighting with them to take it back because one of these times I am going to get in a bad accident. I don't feel safe in the car and I told them each time.
NHTSA ODI #11635970
Mileage unknown · Feb 26, 2024
Electrical SystemEngineSteering
The car has revved high rpm's since purchase, with multiple attempts to get it resolved . Since then, the steering wheel has jerked out of my hand's multiple times, unexpecting, causing the car to jerk while being stopped. The car has also not budged in the middle of traffic while being in drive and the pedal down to the floor u…
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The car has revved high rpm's since purchase, with multiple attempts to get it resolved . Since then, the steering wheel has jerked out of my hand's multiple times, unexpecting, causing the car to jerk while being stopped. The car has also not budged in the middle of traffic while being in drive and the pedal down to the floor until at least a 10 second delay and when doing so the screen that includes the radio, etc panel has completely blacked out and started twitching
NHTSA ODI #11574021