There are 5 owner-reported fuel system complaints for the 2018 GMC Terrainin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
Turbo boost went out in my vehicle and 3 others with the same engine, different makes/models. Vehicles were serviced at Grayling Car Care 4430 M-72, Grayling, MI 49738 (989) 348-3200. Significant power loss, sluggish acceleration, poor fuel economy, and often strange noises (whining, grinding), accompanied by blue smoke from burning oil and a lit check engine light, with the severe risk of catastrophic engine damage from broken parts entering the engine if driven, requiring prompt replacement. It's generally unsafe to drive with a bad turbo, as metal fragments can destroy the engine.
The contact owns a 2018 GMC Terrain. The contact stated while driving approximately 30 MPH, the vehicle decelerated and failed to accelerate over 25 MPH while the accelerator pedal was depressed. The contact stated that a message was displayed on the instrument panel to “Continuously Drive Vehicle Above 30 MPH”. The contact stated that after the vehicle decelerated into engine power mode, the check engine warning light illuminated. The vehicle was taken to the dealer where it was diagnosed that the Diesel Particulate Filter (DPF) failed and needed to be replaced. Additionally, the contact stated that the vehicle was taken to the dealer twice where it was diagnosed that the Diesel Particulate Filter (DPF) needed to be unclogged. The vehicle was repaired; however, the failure recurred. The vehicle was not repaired. The manufacturer was notified of the failure and the contact was informed to contact the warranty company, but no further assistance was provided. The failure mileage was approximately 110,696.
Yesterday morning I noticed a smell of gas around my car. I looked and didn’t see anything. I drove to work. Once I got back to my vehicle after work I could smell gas as I approached my vehicle. I looked under my car and noticed a puddle of gas. I went to the gas station to put enough fuel for me to make it home in my vehicle and as I was putting the gas I noticed a drip under the vehicle. Once I got home and parked my vehicle I looked under the car and there was a rapid and steady drip coming from the fuel tank. The same make, mode and year of my vehicle has been recalled for this.
LEAKING DIESEL FUEL LINE WHILE RUNNING, PARKED AND IN GEAR. SECOND DIESEL TERRAIN FLEET VEHICLE TO LEAK FUEL; OTHER COLLEAGUE HAD THE SAME ISSUE RECENTLY AND WAS ASKED IF SOMEONE CUT THE FUEL LINE. NOW, MINE IS LEAKING.
THIS CAR, A 2018 GMC TERRAIN IS EQUIPPED WITH AUTO START / STOP, A STANDARD FEATURE THAT TURNS OFF THE ENGINE WHEN BRAKE IS APPLIED, SUCH AS AT A STOP LIGHT. THE ENGINE TURNS OFF WHILE BRIEFLY STOPPED AT A STOP SIGN. THIS IS DANGEROUS AND A SAFETY ISSUE. WHILE ATTEMPTING TO PULL INTO A TRAFFIC LANE WITH THE ENGINE OFF, I HAVE EXPERIENCED AN UNSAFE LAG BEFORE THE ENGINE RESTARTS. GM HAS STATED, THE ENGINE CAN BE TURNED BACK ON BY REMOVING YOUR FOOT BRIEFLY FROM THE BRAKE PEDAL. SERIOUSLY ??? WHILE BEHIND ANOTHER VEHICLE, I WILL NOT FOLLOW THIS PROCEDURE. I HAVE NO CONFIDENCE THE ENGINE WILL RESTART AND LUNGE FORWARD, STRIKING THE VEHICLE AHEAD. I WANT GM TO PROVIDE THE CAPABILITY TO PROVIDE THE DRIVER THE ABILITY TO ENABLE OR DISABLE AUTO START / STOP. THE FEATURE IS ALSO TOUTED AS SAVING FUEL WHILE STOPPED. PERHAPS A TINY AMOUNT WHILE AT A LONG LIGHT OR TRAIN CROSSING. CERTAINLY NOT AT A STOP SIGN OR STOPPED BEHIND ANOTHER VEHICLE.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026