Most common 2018 GMC Terrain problems
Share of the 225 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
GMC Terrain complaints by model year
Best Terrain years: 2021, 2016, 2017. Years to avoid: 2024. Compare all years →
2018 GMC Terrain recalls (5)
Power train › Automatic transmission
General Motors LLC (GM) is recalling certain 2018-2019 Chevrolet Cruze and Buick LaCrosse, 2018-2020 Chevrolet Equinox, Chevrolet Traverse and GMC Terrain, 2018 Chevrolet Malibu, 2019-2020 Buick Encore, Buick Enclave, Cadillac XT4, Chevrolet Blazer and GMC Acadia, and 2020 Cadillac XT6 vehicles.
Remedy: GM will notify owners, and dealers will inspect the start-stop transmission accumulator and replace it if any bolts are missing, free of charge. The recall began December 15, 2020.
Service brakes, hydraulic › Foundation components › Disc › Caliper
General Motors LLC (GM) is recalling certain 2018-2019 Chevrolet Equinox, Impala, Cruze, Volt and Bolt EV vehicles, GMC Terrain vehicles, Buick Lacrosse and Regal vehicles, Cadillac XTS and XTS Professional vehicles and 2018 Chevrolet Malibu vehicles.
Remedy: GM will notify owners, and dealers will bleed the vehicle's brake system, free of charge. The recall began October 11, 2018.
Fuel system, gasoline › Delivery › Fuel pump
General Motors LLC (GM) is recalling certain 2015-2018 GMC Canyon, 2016-2017 Buick Envision, 2016-2018 Chevrolet Colorado and Malibu, 2017-2018 GMC Acadia, 2018 Buick LaCrosse, Cadillac ATS, Chevrolet Equinox, and GMC Terrain vehicles.
Remedy: GM will notify owners, and dealers will replace the high pressure fuel pump, and high pressure fuel pipe, free of charge. The recall began July 2, 2018.
Air bags › Air bag/restraint control module
General Motors LLC (GM) is recalling certain 2018 GMC Terrain vehicles. The sensing diagnostic module (SDM) that senses a crash and deploys the necessary air bags may not power down correctly when the vehicle is shut off, causing it to be inoperative when the vehicle is restarted.
Remedy: GM will notify owners, and dealers will reprogram the SDM with updated software, free of charge. The recall began June 29, 2018. Owners may contact GMC customer service at 1-800-462-8782.
Power train › Driveline › Driveshaft
General Motors LLC (GM) is recalling certain 2018 Chevrolet Equinox and GMC Terrain vehicles and 2017-2018 GMC Acadia vehicles. The right front intermediate driveshaft may fracture and separate while driving.
Remedy: GM will notify owners, and dealers will replace the right front intermediate drive shaft assembly, free of charge. The recall began August 25, 2017.
What 2018 GMC Terrain owners say
Brakes all 83 →
The contact owns a 2018 GMC Terrain. The contact stated that while driving at approximately 35 MPH going over a hill, the brake pedal was depressed but was firm and failed to depress as needed. The engine power reduced message was displayed and flashed on and then off. The brake assist warning light was illuminated. The service transmission message was displayed. The contact continued to depress the brake pedal until the vehicle responded as needed. The driver was able to pull into a parking lot, and the vehicle rolled to a stop. While driving, the engine misfired. Additionally, the vehicle failed to fully shutoff. The vehicle was towed to the local dealer, where it was diagnosed that the brakes had locked up and that the vacuum pump needed to be replaced. The contact was also informed that the cam shaft had fractured inside the engine. …
The contact owns a 2018 GMC Terrain Denali. The contact stated while the contact's daughter was driving, the brake pedal was depressed, however the vehicle failed to stop as intended. In addition, the contact stated that the brake pedal was unusually hard when depressed. The vehicle was taken to the dealer where the vehicle was purchased. The contact stated that the service brake vacuum pump failed while the vehicle was at the dealer. The vehicle was diagnosed with a failed service brake vacuum pump and a failed engine. The contact was informed that the service brake vacuum pump, the CAM Shaft and the engine needed to be replaced. The vehicle was repaired. The contact stated that the failure was a known failure of the vehicle. The manufacturer was not made aware of the failure. The failure mileage was approximately 260,000.
Engine & cooling all 56 →
The contact owns a 2018 GMC Terrain Denali. The contact stated while the contact's daughter was driving, the brake pedal was depressed, however the vehicle failed to stop as intended. In addition, the contact stated that the brake pedal was unusually hard when depressed. The vehicle was taken to the dealer where the vehicle was purchased. The contact stated that the service brake vacuum pump failed while the vehicle was at the dealer. The vehicle was diagnosed with a failed service brake vacuum pump and a failed engine. The contact was informed that the service brake vacuum pump, the CAM Shaft and the engine needed to be replaced. The vehicle was repaired. The contact stated that the failure was a known failure of the vehicle. The manufacturer was not made aware of the failure. The failure mileage was approximately 260,000.
The contact owns a 2018 GMC Terrain. The contact stated while driving 40-45 MPH, the vehicle started coasting and stopped unintendedly. The contact stated that the vehicle drove for a while and then coasted and stopped. The message that the "Engine Power Reduced" was displayed. The contact stated that the brake system warning light was also illuminated. The vehicle was towed to an independent mechanic who determined that the camshaft had disintegrated into the engine. The mechanic informed the contact the vehicle was unrepairable. The vehicle was not repaired. The local dealer was not contacted. The manufacturer was not made aware of the issue. The failure mileage was approximately 60,000.
Transmission & drivetrain all 42 →
My husband and son were involved in an almost fatal accident on 07/08/23 in our 2018 Terrain. My husband described that the vehicle spontaneously veered to the right uncontrollably, he was unable to steer to correct the vehicle, unable to brake, they went airborne, hit several poles and a transformer, rolled and flipped several times. All the airbags deployed.After the accident, I found a recall notice from back in 2017, I believe, regarding the drive train. My husband was extricated from the vehicle. My son wasble to cut the seatbelt and crawl out the window. From what my husband explained (he was the driver), this sounds like what they experienced during the collision. I never received a recall letter from GM as this is something I would of taken care of and have got repaired. Please see the photos and the recall I found. …
The contact owns a 2018 GMC Terrain. The contact stated that while driving at various speeds, there was an abnormal grinding sound coming from the vehicle while transitioning to 4WD. The contact continued driving and the driving sound became more frequent while shifting into 4WD. Upon inspecting the vehicle, the contact discovered that the driveshaft had detached and was hanging down from the suspension. An independent mechanic was contacted, and the contact was informed about NHTSA Campaign Number: 17V516000 (Power Train); which the mechanic associated to the failure. The contact called two local dealers and was informed that the VIN was not included in the recall. The manufacturer was notified of the failure, and the contact was referred to the NHTSA Hotline to report the failure. The vehicle was not repaired. The failure mileage was approximately 160,000.
2018 GMC Terrain engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 1.6L 4-cyl turbo diesel | 6-speed automatic | FWD | 28 / 39 / 32 |
| 1.6L 4-cyl turbo diesel | 6-speed automatic | AWD | 28 / 38 / 32 |
| 1.5L 4-cyl turbo | 9-speed automatic | FWD | 26 / 30 / 28 |
| 1.5L 4-cyl turbo | 9-speed automatic | AWD | 24 / 28 / 26 |
| 2.0L 4-cyl turbo | 9-speed automatic | FWD | 22 / 28 / 24 |
| 2.0L 4-cyl turbo | 9-speed automatic | AWD | 21 / 26 / 23 |
EPA ratings. Class: Small SUV.
Frequently asked questions
Is the 2018 GMC Terrain a good car?
Based on 225 owner complaints filed with NHTSA, the 2018 Terrain rates average: about as many complaints as a typical year of the Terrain at the same age. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2018 GMC Terrain?
The brakes — 83 complaints, 37% of all complaints for this model year, most often about power assist › vacuum. Next are the engine & cooling (56) and transmission & drivetrain (42).
How many recalls does the 2018 GMC Terrain have?
There are 5 recalls for the 2018 GMC Terrain, the most recent from October 29, 2020 (automatic transmission). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the GMC Terrain?
The best years by complaints, compared at the same age, are 2021, 2016 and 2017. Years to avoid or approach with caution: 2024. See the full GMC Terrain years comparison.
At what mileage do 2018 GMC Terrain problems happen?
The median mileage reported in complaints is about 19,000 miles; 66% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.