2012 GMC Terrain Powertrain (other) Problems

1. The engine suddenly lost power while driving during evening rush hour and the vehicle would no longer accelerate. 2. Because the vehicle could not maintain speed, I was unable to keep up with traffic, creating a serious safety hazard that could have resulted in a major accident. 3. The vehicle has been inspected by an independent service center for diagnosis. 4. During the incident, the “Engine Power Reduced” warning indicator illuminated just before the loss of power occurred. 5. As the vehicle slowed and came to a complete stop at an intersection, it remained unresponsive. When the traffic light turned green, the vehicle would not accelerate at all.

NHTSA ID

11699710

Incident

Feb 12, 2025

GMC Consumer Relations Subject: Structural Undercarriage Safety Defect – 2012 GMC Terrain SLE Vehicle Information: Year/Make/Model: 2012 GMC Terrain SLE VIN: [XXX] Mileage at Purchase: 148,305 Date of Purchase: [XXX] Location: Rochester, New York I am filing a complaint regarding a severe undercarriage safety defect in my 2012 GMC Terrain SLE. The rear undercarriage of this vehicle shows heavy structural corrosion on suspension brackets and mounts. The condition produces clanging noises during normal driving, and an independent licensed mechanic has refused to work on the vehicle because the suspension integrity is unsafe. When I returned the vehicle to the dealer, I observed additional brackets being attached under the rear subframe area, suggesting reinforcement of compromised structural points. This confirms that the corrosion directly affects suspension geometry, alignment, and stability. This corrosion is not cosmetic. It is advanced structural deterioration affecting the mounting points for trailing arms and lateral links. These components are critical to safe turning, stability, and control. The corrosion compromises the ability of the suspension to keep the wheels aligned, creating serious risks of loss of control or wheel separation. What makes this more alarming is that the vehicle passed a New York State safety inspection on 07/13/2025, yet within days a mechanic refused to perform unrelated service because of the undercarriage condition. This raises questions not only about inspection validity, but also about the underlying durability and corrosion. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11687398

Incident

Sep 7, 2025

hello i'm writing this letter to inform you about my 2012 Terrian i have had nothing but problems with the motor and now the muffler system i have had all recalls done on this and GM is well aware of this problem i have a dealer ship to replace the timing in this motor and still uses oil and still have all the problems after the recalls have been fixed now they want me to pay over $3,000 to have new catalytic converters fixed on it now after paying $2800 for a new timing seems to me GM likes to fix the cheap stuff on these cars and make customers pay for the expensive parts must people can't afford this and junk the vehicle i will not i'm going to fight for what is right the dealer ship even told me when i took it back in to see what the code was for that GM is well aware of it and not worth putting the money into the car this is not right for customers to spend this kind of money GM needs to handle this.

NHTSA ID

11582154

Incident

Apr 10, 2024

The contact owns a 2012 GMC Terrain. The contact stated that while driving at 65 MPH, the vehicle inadvertently lost all motive power. The contact was able to pull to the shoulder of the roadway, where the vehicle was able to restart, but failure persisted. The traction control warning light was illuminated. The vehicle was towed to an independent mechanic, who was able to diagnose the failure, but the contact was unable to recall the specifics. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was unknown.

NHTSA ID

11578481

Incident

Aug 13, 2023

My 4 cyl. AWD GMC Terrain has had excessive oil use which caused premature failure of the timing chain, loss of power/compression, blown engine, damage to exhaust manifold, cellinoids, and melted the catalytic converter. Its was a road safety, poor emissions due to failed catalytic converter. Headlights are too bright for oncoming traffic at night. Another road & safety hazard. Auto warranty is refusing to cover parts listed above caused by the timing chain and excessive oil consumption problems.

NHTSA ID

11567406

Incident

Dec 24, 2023

The contact owns a 2012 GMC Terrain. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently lost motive power. The contact was able to coast the vehicle to the shoulder of the roadway, and the vehicle failed to restart. No warning lights were illuminated. The vehicle was not taken to the dealer nor an independent mechanic. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was unknown.

NHTSA ID

11565815

Incident

Jan 16, 2024

I still have more to add to my other complaint. The fire started with alternator apparently there were crossed wires took alternator back to Orielys where I got it warrented out fixed the expanded wiring and replaced a hose and other things damaged by the little fire. Then after that things kept getting worse. Then it was spark plugs that were rusted that I replaced eventually I complained back to the dealership I got the car from and they agreed to help repair it after a posting by me on fb that I wasent a happy customer basically and that I literally had a sitting duck. Turns out the timing chain needed to be replaced and other little things. I've replaced O2 sensors camshaft sensors gaskets in catalytic converter had it inspected thinking it was a clogged exhaust the excessive oil usage was insane I would be going through 5quarts twice a month! I'm just tryna have a DECENT WORKING VEHICLE for my kids and I. I literally can't keep a job because I DONT HAVE RELIABLE transportation....I've put sooooo much money into this vehicle and now I might have a blown gasket!!! And that's because I haven't even been driving the vehicle. I got the car on Jan 7th 2021 with 129,043 miles on it as of today it has a total of 164,627 miles on it meaning in between the two years that I've owned the vehicle I have only put a total of 35,584 miles on it.....for it to have this many problems for so little mileage is INSANE!!! my kids were in the car with me today when the car started smoking like crazy from under hood and exhaust I pulled over turned the car off and took my baby off car seat in all and got away from vehicle thinking it was on fire again. I popped the hood and notice it was coming from under manifold.....meaning its probly a blown gasket after I just replaced the camshaft sensor AGAIN......it's ridiculous all the stuff thats going wrong with this vehicle with so little mileage that's been put on it.

NHTSA ID

11492037

Incident

Nov 2, 2022

First off before I got the car it had gone through a tune up. About a couple months after I got the car little things started to happen it would rock back and forth while idling I thought it was kind of an indicator that it needed oil but the percentage was still at a decent range and telling me it didn't need oil plus I hadent driven it 3000-5000 miles. Then engine light came on had it inspected codes ran came back telling me something about Throttle body So I purchased a whole new throttle body in Prosser at dealership costing me some booko buks and swapped it out when I got back home I then took it for test drive along with my 4 kids in the vehicle with me and then a little ways about 20 mins driving engine power reduced light came on along with stabilitrak and eventually lost power I was stranded in the middle of summer in the middle of nowhere with my kids windows rolled down ppl drove by and asked if I needed help and eventually came back with jumper cables tried to jump me but the car wouldn't budge I then left the car there overnight and took battery out to have it inspected the next day IT WAS FRIED (over 4 yrs old) so I had to purchase a new one costing me roughly 150 buks then took it back to where my car was stranded put it in and alarm went off and I clicked the button on key ring stuck it in ignition shit the door behind me locking keys in car while vehicle was still running and had to bust a window out to get to em. Got into car drove off made it back to my apt left it running outside while I went inside to get some stuff before I THOUGHT the problem was solved it shut off again.....I then had to replace the alternator costing me another pretty penny....about a couple weeks later I was starting a new job at a assisted living facility and arrived 10 mins early shit car off a noticed smoke coming from under hood I was confused because where the smoke was coming from couldn't have been it overheating I popped the hood and my car was on fire!!!!

NHTSA ID

11492036

Incident

May 13, 2021

MASSIVE OIL CONSUMPTION!! Ever si Fr the purchase of the vehicle there has been massive oil consumption leak. Taken back to the dealer for service to take care of the problem, they claim they don’t see a problem! This car has been oil leaking and also draining oil somewhere to the engine causing also power rain engine issues and also contact oil light on. Reported to GMC as well and corporate, no response! This vehicle has cut off and lost power because of oil consumption on highway with my children in the car! I have been emailing with no avail! This matter needs to be rectified immediately! It is a death trap!

NHTSA ID

11476606

Incident

Mar 8, 2019

I just spent 1,600 dollars to replace the timing chain. I know their were recalls on this, I was wondering why my vin and model were not included in these recalls?

NHTSA ID

11445722

Incident

Dec 27, 2021

Excessive oil consumption caused blown engine

NHTSA ID

11441082

Incident

Nov 18, 2021

I am having trouble with these things now. The powertrain especially I have not had accident yet but it keeps going dead on me in the middle of driving down road. Causing me to have to put in neutral and restart. At this time the steering goes out. This needs to be repaired before an accident does happen. The drivers seat does not move forward or backwards. The tire pressure warning does not warn until it is at 20 psi.

NHTSA ID

11423849

Incident

Jun 28, 2021

Says powertrain control module failure. Also oxygen sensor on the my gmc app. It keeps cutting off in the middle of road.

NHTSA ID

11419064

Incident

May 28, 2021

BURNING OIL ENGINE POWER REDUCED BUCKING STALLING

NHTSA ID

11394392

Incident

Jun 23, 2016

Mileage

50 mi

TL* THE CONTACT OWNS A 2012 GMC TERRAIN. THE CONTACT STATED THAT HE WAS INFORMED THAT THERE WAS NO OIL INSIDE THE VEHICLE UPON TAKING THE VEHICLE TO AN INDEPENDENT MECHANIC FOR THE FIRST OIL CHANGE. NO WARNING LIGHTS APPEARED ON THE INSTRUMENT PANEL PRIOR TO THE DISCOVERY. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE AND THE CONTACT WAS GIVEN A VOUCHER TO HAVE THE VEHICLE INSPECTED. THE CONTACT WAS INFORMED THAT THE FAILURE WAS DUE TO DEFECTIVE PISTON RINGS THAT WERE TOO EXPENSIVE TO BE REPLACED. AS A RESULT, THE ENGINE BECAME INOPERABLE. THE VEHICLE WAS DIAGNOSED WITH ENGINE FAILURE. PRIOR TO THE ENGINE FAILURE, THE CONTACT ALSO STATED THAT THE VEHICLE REVVED AND ACCELERATED INDEPENDENTLY WITHOUT WARNING, WHILE DRIVING AT VARIOUS SPEEDS. THE CONTACT NOTED THAT PRIOR TO THE ENGINE FAILURE, BOTH WINDSHIELD WIPERS WERE DEFECTIVE DUE TO THE WINDSHIELD WIPER TRANSMISSION. BOTH WINDSHIELD WIPERS WERE REPLACED ON THREE SEPARATE OCCASIONS. THE VEHICLE WAS NOT REPAIRED. THE FAILURE MILEAGE WAS APPROXIMATELY 55,000.

NHTSA ID

11383093

Incident

Aug 1, 2018

Mileage

55,000 mi

CAR IS BURNING EXCESSIVE AMOUNT OF OIL. NOW THE ENGINE HAS SEIZED UP

NHTSA ID

11377311

Incident

Dec 1, 2020

Mileage

133,000 mi

CODE-P0014-CAMSHAFT POSITIONB TIMING OVER-ADVANCED OR SYSTEM.CODE-P0300 RANDOM/MUITIPLE CYLINDER MISFIRE.COMPUTERIZED ENGINE ANALYSIS.RECALLS#50490-50491

NHTSA ID

11375295

Incident

Nov 15, 2020

Mileage

95,860 mi

HAVE A SERIOUS OIL CONSUMPTION PROBLEM HAVE TO HAVE OIL CHANGED EVERY 500 MILES, IT STARTS TO SHAKE WHEN START UP IT TURNS OFF KEEP GETTING CAMSHAFT CODES ALSO GOT MISFIRE CODE

NHTSA ID

11365867

Incident

Sep 7, 2018

Mileage

99,000 mi

VEHICLE SHUTS OFF WHEN SLOWING TO A STOP AND HAVE TO RESTART IN ORDER TO ACCELERATE. THAT WAS LOOKED AT AND 'FIXED' AND NOW THE VEHICLE SHAKES WHEN SLOWING DOWN AND HEADLIGHTS DIM AS IF IT IS TRYING NOT TO SHUT OFF. ENGINE IS VERY ROUGH AND RATTLES WHILE STARTING TO ACCELERATE AND ACCELERATING. WHEN BRAKES ARE PUSHED THE CAR STARTS TO TURN OFF WHILE IN MOTION. WHEN STOPPED, CAR SHAKES AND THERE IS A VERY HARD KNOCKING COMING FROM THE ENGINE.

NHTSA ID

11280447

Incident

Nov 12, 2019

Mileage

80,000 mi

TRANSFER CASE WENT AT 67K JUST BOUGHT IT USED AT 63K. I HAD NO WARRANTY ONLY 60 DAY FROM USED DEALER I BOUGHT IT FROM. RUINED MY PASSENGER SIDE AXEL ALSO WHEN TRANSFER CASE WENT $1137 WAS THE BILL. 500 FOR USED CASE 16K 170 FOR AXEL 30 FOR FLUID REST IN LABOR. SHOULD BE A RECALL CAR SOUNDED AWFUL BACK UP AND IN DRIVE LOSS A BIT OF POWER WHEN DRIVING. ALSO.

NHTSA ID

11266555

Incident

Aug 14, 2019

Mileage

67,000 mi

TL* THE CONTACT OWNS A 2012 GMC TERRAIN. WHILE DRIVING VARIOUS LOW SPEEDS, THE VEHICLE STALLED AND SHUT OFF WITHOUT WARNING. AFTER THE VEHICLE WAS RESTARTED, THE VEHICLE JERKED AND THEN RESUMED NORMAL OPERATION. THE DEALER AND MANUFACTURER WERE NOT NOTIFIED OF THE FAILURE. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE FAILURE MILEAGE WAS APPROXIMATELY 101,000.

NHTSA ID

11266190

Incident

Sep 30, 2019

Mileage

101,000 mi

WHILE DRIVING A SHORT DISTANCE ON A CITY STREET I HEARD A THUD FOLLOWED BY A GRINDING NOISE AND LACK OF POWER. VEHICLE WAS TOWED TO A TRUSTED MECHANIC THAT I HAVE KNOWN AND USED FOR YEARS. DIAGNOSED WITH A CRACK IN THE TRANSFER CASE. MECHANIC HAD DIFFICULTY FINDING A PART AND WAS INFORMED BY SOMEONE AT THE GMC DEALER THAT THIS PART WAS ON BACK ORDER BECAUSE OF AN ISSUE KNOWN BY GMC BUT A RECALL HAD NOT BEEN ISSUED. NEW PART WOULD NOT BE AVAILABLE FOR OVER A MONTH AND REPAIRS WERE NEEDED SINCE IT IS MY PRIMARY VEHICLE. A USED PART WITH A WARRANTY WAS FOUND AND WAS INSTALLED FOR A TOTAL OF $1500. VEHICLE POWER TRAIN WARRANTY WAS EXPIRED. LESS THAN 3 MONTHS AFTER TRANSFER CASE WAS REPLACED WITH A USED PART - THE REPLACEMENT PART CRACKED IN THE SAME EXACT SPOT AS THE ORIGINAL. LUCKILY, THE PART WAS STILL COVERED BY A WARRANTY BUT LOCAL MECHANIC RECOMMENDED DIAGNOSIS BY DEALER TO DETERMINE IF THERE IS AN ISSUE WITH THE TRANSMISSION. CONTACTED GMC TO SEE IF THEY WERE AWARE OF THE ISSUE AND THEY SAID THEY WERE NOT.

NHTSA ID

11265291

Incident

Jun 28, 2019

Mileage

81,534 mi

REAR MAIN SEAL LEAK, PVC VALVE FREEZES FROM WATER CONDENSATION AND LOW TEMPERATURES: CAUSING CRANK CASE GASES TO BECOME HIGHLY PRESSURIZED AND BLOW OUT THE REAR MAIN SEAL OF THE ENGINE CAUSING A MASSIVE OIL LEAK ON THE ROAD TO THE REAR TIRES POSSIBLY CAUSING LOSS OF CONTROL TO THE REAR WHEELS CAUSING THE POSSIBILITY OF A FATAL LOSS OF CONTROL VEHICLE ACCIDENT. OTHER POSSIBILITIES OIL COATING ENTIRE UNDERCARRIAGE OF VEHICLE CAUSING A VEHICLE FIRE, CATISTROPHIC ENGINE DAMAGE CAUSING LOSS OF CONTROL, ENVIROMENTAL IMPACT 5 QUARTS OF OIL ON THE HIGHWAY.

NHTSA ID

11170201

Incident

Jan 13, 2019

Mileage

10,800 mi

I ALSO HAVE A 2012 GMC TERRAIN THAT HAS AN OIL CONSUMPTION ISSUE THAT HAS CAUSED COMPLETE ENGINE FAILURE. APPROXIMATELY 2.5 WEEKS AGO THE CAR WOULDNT START. ENGINE WOULD TURN OVER BUT NOT START. I THOUGHT THAT IT MIGHT BE THE FUEL PUMP. HAD IT TOWED TO MY MECHANIC SINCE IT HAS 87K MILES AND OUT OF WARRANTY. SO I WENT TO CHECK THE STATUS OF THE CAR AND THE FIRST THING I WAS TOLD WAS THERE WAS NO OIL WHEN THEY CHECKED IT. THEY ADDED 4 QUARTS BEFORE TRYING TO DIAGNOSE THE PROBLEM. MIND YOU THE OIL WAS CHANGED 3K MILES AGO AND OIL LIFE MONITOR SAID IT HAD 54% LIFE LEFT. THEY RAN THE CAR FOR CODES AND THE ONLY CODE THAT CAME UP WAS FOR THE TIRE PRESSURE SYSTEM, ALSO AN ISSUE WITH THE TERRAIN. NO ISSUE WAS FOUND WITH FUEL PUMP OR SENSORS. SPARK PLUGS WERE REPLACED DUE TO THEM BEING ALL FOULED UP. THAT DIDNT FIX THE ISSUE SO IT WAS DETERMINED THAT IT MUST BE THE TIMING CHAIN JUMPED. AT THAT POINT I HAD IT TOWED AGAIN TO THE DEALERSHIP I PURCHASE IT FROM. I WAS TOLD IT WOULD BE 125.00 TO RUN A DIAGNOSTIC. FINE. SO I GET A CALL THE NEXT DAY THAT IT WAS INDEED THE TIMING CHAIN. I ASKED THE SERVICE GUY WHAT WOULD CAUSE THIS AND I WAS TOLD POOR LUBRICATION OR LOW OIL PRESSURE. THATS WHEN I STARTED TO EXPLAIN THAT THE FIRST SHOP HAD TO PUT 4QTS OF OIL IN BC IT WAS BONE DRY. I ASKED ABOUT THE VIN SPECIFIC LETTER I RECEIVED LAST YEAR,2017, ABOUT THE OIL CONSUMPTION ISSUE AND ISNT THAT WHY THERE WAS NO OIL AND HENCE CAUSING THE TIMING BELT TO JUMP. HE ANSWERED "NO". THEN TOLD THAT UPON FURTHER INSPECTION, THE VALVES WERE BENT SO WE WERE NOW LOOKING AT 3500 TO FIX OR 6K TO REPLACE THE ENGINE WITH ANOTHER PROBLEMED ENGINE. SO THAT IS WHEN I CONTACTED THE TOLL FREE CUSTOMER SERVICE LINE ABOUT THE SITUATION. THEY TOLD ME TO GO BACK TO DEALERSHIP AND SPEAK TO THE CUSTOMER EXPERIENCE MANAGER.

NHTSA ID

11153179

Incident

Nov 5, 2018

Mileage

87,228 mi

EXCESSIVE ENGINE OIL CONSUMPTION. TIMING CHAIN FAILURE. PISTONS, RINGS, EXHAUST MANIFOLD, MUFFLER, DOOR REGULATOR, WIPER MOTOR, TRANSMISSION FAILURE. VEHICLE CANNOT BE DRIVEN

NHTSA ID

11115439

Incident

Jul 26, 2018