Power Train Problems of GMC Terrain - part 2

[xxx] once again while diving down the road 45mph Terrain once again goes in to park ,I was lucky the lady behind me wasn't to close . Also I contacted onstar when I was able to get vehicle moving at the store . . I told her what happen she ran diagnostics while parked at store said there was no codes I let onstar know this has happened several times. . I had no warning, no indication, no lights came on. And I also let her know that this same vehicle was still stalling I was at intersection and the auto/stop is always on it will not let you bypass or default took it to dealership who I bought cpo back when it first would not let me turn it off cause its stalls at stop signs ,red lights etc crazy thing is if you turn the ac on it cranks up , if you hit the door unlock it starts. . . Thats not normal GMC knows that the dealership whom sold me cpo that wasn't the misleading is beyond crazy. . Gsm cussed me out it comes with life time warranty but when I had it towed right after I bought it 2 months . . I was talking about what the mechanics had said that this vehicle was in prior flood and accident GMC onstar has a different VIN then the one that on the vehicle. . The doors are not original I can see the inside of steering wheel and on dash where they said air bags were deployed and they did a [xxx] job hiding it . . . I paid over 32k for this 2020 Terrain that was advertised as cpo with 1 owner in florida they showed me a fraudulent carfax, I pulled up my own and it came from new york . . This vehicle is not safe to drive but I dont have any other options. . I have made complaint with both GMC and my finance company whom also wrote complaint on dealership and the told me I could rewind the loan but when I told dealership I knew that they sold me a vehicle that was not cpo and what I learned he came at me at dealership infront of workers and customers . . The vehicle just going to end up getting myself killed or someone else. . Semi had to run off road to avoid hitting me information redacted pursuant to the freedom of information act.

See all problems of the 2020 GMC Terrain 🔎.

The contact owns a 2024 GMC Terrain. The contact stated that while driving at an undisclosed speed and preparing to complete a left turn, there was an abnormal pop coming from underneath the vehicle. No warning lights were illuminated. The vehicle was taken to the dealer, who determined that the driveshaft had fractured. The vehicle was repaired. The contact stated that several days later the contact heard a loud pop, prompting the contact to take the vehicle back to the dealer, who was unable to duplicate the sound. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 1,200.

See all problems of the 2024 GMC Terrain 🔎.

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.

See all problems of the 2021 GMC Terrain 🔎.

Timing chain. It had no warning and failed due to poor design and gm in europe fixed/addressed the issue by installing a plate behind the tensioner a part that isn’t available in the us.

See all problems of the 2018 GMC Terrain 🔎.

Brake vacuum pump premature failure. As you see GMC, Terrains, in equinox, I have an issue, while the engine it's on while driving etc, if this bark fails, you will have an issue I'm trying to stop. This is a known problem or gm. And as of now, they have not come out with a solution or a recall for this problem. This problem has caused many customers. To lose thousands of dollars, he repairs. I'm not covered by the warranty. This should be addressed and repaired as soon as possible as it may cause someone else to lose their life. Second problem is the 9 speed transmission transmission lack power when trying to gain speed as you enter the highway. Lastly they blamed the selenoids etc. Lastly the pulley belt retention broke down premature with only 68k miles. This is an ongoing problem gm is well aware and tries to hide or fix. When someone buys a vehicle we expect to last longer than 100k miles.

See all problems of the 2019 GMC Terrain 🔎.

Vehicle is consuming excessive amount of oil in short drive time up to 3qt in less than 1000 miles. With no oil leaks. Vehicle only has 139840 miles. Has regular oil changes and services done.

See all problems of the 2014 GMC Terrain 🔎.

When accelerating, the engine revved up, switched itself from drive to park, resulting in complete loss of control and the vehicle coming to a sudden stop. The car behind narrowly avoided a rear-end collision by swerving around me. The malfunction indicator light came on for the first time, and the vehicle would not switch out of park. After turning the ignition off and on again, the vehicle would switch out of park. The GMC service inspector ran diagnostics and found fault codes related to the transmission valve components that must be replaced.

Transmission dropped complete out of gear while driving. Got vehicle moving again. Took to dealership. Found complete internal transmission failure at 6779 miles. Transmission replaced with new unit. New transmission has erratic / hard shifts. Found replacement transmission leaking fluid due to front pump / porous case at 14800 miles. Customer satisfaction program n232433890 issued may 16, 2024.

The contact owns a 2018 GMC Terrain. The contact stated that the transmission was shifting gear erratically. The contact stated that the doors were locking and unlocking independently, and the instrument cluster was blank. There was an abnormal beeping sound coming from the vehicle. Additionally, the contact stated that while at a traffic light, the auto start/stop feature delayed to respond. Onstar was alerted, but the contact declined to perform the service. The contact was in contact with the independent mechanic who sold the vehicle, but no assistance was provided. The local dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 130,000. The VIN was not available.

The contact owns a 2022 GMC Terrain. The contact stated that while the vehicle was idling, there was while smoke coming from the exhaust pipe. The vehicle was taken to the dealer and was diagnosed with oil intrusion into the pistons, causing transmission failure. The contact was informed that the transmission needed to be replaced. The dealer changed the oil and advised the contact to return every two thousand miles. On a separate occasion, the contact stated that while her husband was driving at various speeds, the vehicle hesitated and jerked. There were no warning lights illuminated. The contact stated that the failure had progressively worsened. The manufacturer was not notified of the failure. The failure mileage was 18,686.

See all problems of the 2022 GMC Terrain 🔎.

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.

See all problems of the 2012 GMC Terrain 🔎.

My car lost oil while I was driving. I also lost power. I had my car over to a garage and the mechanic diagnosed it was a ruptured rear main seal caused by a frozen pcv system. Gm knows about the problem but has not recalled it. It is very expensive to repair. And because the manufacturer knows about it but never told the consumer, is fraudulent.

See all problems of the 2017 GMC Terrain 🔎.

Driving home from dropping my daughter off at school. When slowing down at stop sign, car locked up brakes completely, almost went through stop sign, car shut down engine and placed vehicle in park. Diagnosis is a vacuum pump failure, causing reluctor wheel to spin freely from camshaft. This happened without warning at 70k miles. Diagnostic report from three weeks prior showed no bad diagnostics with engine or drivetrain components, or brake components. Had to have car towed from intersection where I was impeding traffic due to sudden failure. Garage is concerned regarding potential for debris and engine damage, as well as timing issues due to sudden failure of vacuum pump. Gm has authorized vacuum pump recalls on other makes from prior years, not Terrain for some reason. This is how becoming highly reported failure among GMC/chevy vehicles with shaft driven vacuum pump design between 2019-2022. Gm has stopped using this design on 23 and newer models. They should absolutely recall these older models for this issue. Sudden vacuum pump failure can lead to unrepairable engine damage due to design.

While driving the car went into power save mode and completely shut down. There were no prior lights or warnings that the car was having issues. While driving at 45mph on a busy road it just suddenly shut down. It would not move to get it out of the road. I was almost hit from behind. After the car was towed, it was diagnosed as a broken vacuum pump and exhaust camshaft. Our Terrain only has 67,773 miles at the time of the incident which was unfortunately just outside of warranty. Since this incident and the repair, the car has had to go back to the shop 4 times. It is still not driving correctly and stalled as I pulled out onto a main road almost causing an accident. Still working on getting it diagnosed and repaired correctly. The mechanics I have spoken to indicated this engine/car is known for these issues. Without any warning lights or signs of issues prior it really put us in a dangerous situation.

The engine in my 2020 GMC Terrain is consuming oil at an alarming rate, burning through a full supply within one hour of operation. This excessive oil consumption has repeatedly caused significant damage to the coils and spark plugs, rendering them ineffective within 24 hours. The issue has led to multiple cylinder misfires, poor vehicle performance, and a transmission stall, posing a serious safety risk while driving. The GMC mechanic at jim ellis Buick GMC diagnosed the problem as internal damage to the pistons, which they state requires a full engine replacement. They also confirmed an internal oil leak within the engine, which is contributing to bad emissions and further degrading vehicle performance. This defect not only compromises the reliability and safety of the vehicle but also raises significant environmental concerns due to the excessive oil burning and emissions. I am requesting a thorough investigation to address this issue and determine whether it is part of a broader manufacturing defect affecting similar vehicles.

My vehicle only has 78,000 miles on it and the timing chain needs to be replaced?! this is no longer under warranty because it’s been over 5 years but this should last a life time. Now I have a car that doesn’t start or run that I have to make payments on and no one wants to do the work on my car! I looked online and a bunch of people are having the same issue with the same exact car at similar mileage and the same issue! GMC needs to do a recall on this issue, many people are losing money and it’s a financial crisis.

The contact owns a 2014 GMC Terrain. The contact stated while at a complete stop at the red traffic light, the doors were making locking and unlocking sounds. The contact stated upon depressing the accelerator pedal to resume driving, the vehicle failed to exceed 25 mph. The messages "service stabilitrak" and "service power steering" were displayed, and the check engine warning light was illuminated. The contact was able to drive to the residence. The vehicle was towed to the dealer, where it was being diagnosed. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 159,500.

Gear selector.

First time I had problems with my 2021 Terrain I took it to victory GMC on 9/20/24. At the it had 45,000 miles. Every time I would drive and accelerate it would shake extremely bad in the floorboard. There was also transmission fluid leaking. I picked the car up on 9/27/2024 and was advised that both front axles were replaced, which corrected the shaking and the driver side axle seal was replaced, which was where the leak was coming from. This was covered under warranty but at 45,000 miles I should not have been already having axle problems or any type of leak. I dropped my car off again on may 5, 2025. When I called them the day I made the appointment I let them know I had a service transmission message show up and then go away, I told them it’s taking longer to kick into gear when I’m on the highway, I told them it revs up past 4 1/2 rpms at times when it had not previously done this and it just sounded like the engine is working harder. I also told them I had a check engine line come on and go off and it was code p2271 which was an oxygen sensor code. I also told them when I had the oil changed. They told me there was a slight oil cooler leak starting. All this was supposedly addressed when I dropped it off to be serviced on 5/5/25. I was called on five 625 to pick up my vehicle notifying me that they found no issues. They were unable to verify concern concerning my check engine light. They said there was no oil cooler leaking, it was just slightly seeping, so not considered a leak. And they said no transmission concern operated as designed. Fast forward to may 9, 2025… I got in my car in the morning and once again the check engine light was on. I drove it straight to GMC and had them put the reader on it. The oxygen sensor code came on. The same code I told them about on the 5th that they said was fine on the 6th. I made an appointment once again to get this check engine light looked at although the check engine light is not on at the moment again.

Bought new car August 16th 2024. Few days later, I was turning left at a light and the car lost power as I was turning and error messages came up on the dash screen saying service transmission. I also observed that the cars gear indicator went to park by itself even though the car was still moving. Pushed the engine start button and car came back on and I switched the gear to drive. Took car in on the 19th to get looked at. Week later, driving down the city street going 40-45 mph, car lost power again and car gear indicator switched to park again, service transmission indicator came up and low fuel indicator came up even though I had over 1/2 a tank left. Took in to dealership on August 26th, 2024. Over this weekend, my wife was driving home from up north at a very busy freeway intersection and the car lost power again and luckily she was able to get over to the shoulder. It took some time but she was able to get the car restarted and made it home. There is something seriously wrong with this particular vehicle where we do not want to even drive it. This car has less than 500 miles on it and has lost power three times in three weeks.

The vehicle is a 2020 and should not already be having electrical issues. The vehicle repair is over 5k for needing a starter motor, water pump and drive belt. A starter should last up to 100k miles and water pump should last 10 years not 4. This vehicle is a lemon and should not have so many issues.

While driving I had to push the brake to the floor and a light came on saying reduced engine power. I pulled over right away and had my car towed to mechanic. The vacuum brake pump exposed and parts went into the engine. The mechanic got all the parts out but now engine has low compression and needs a new timing chain. This is over $3,000 so far. Gm recalled other vehicles with the exact same pump ? why not the Terrain.

Hello. As I come to a complete stop the car will go into auto-stop. After releasing the brake pedal the car will jerk forward . As I press the gas pedal the car jerks and shakes . The rpm jumps way up and the mph say low. . There's been times I try to accelerate and the car with jerk and put itself into park. . In the middle of traffic. . Heart pounding to say the lease. I also notice theres alot of black liquid dripping for the front right side under the front bumper. There were no problems with the car or lamp indicating there were before this. I went to where I brought the car and they told me my warranty expired and that I will need to pay $265 just to diagnose the issue. I didnt have that money. I do have a car code reader and I did my best to find a solution. Codes p0700, p171d, and p187d all appear on my device. I then looked up recalls and my VIN wasn't confirmed. . But I am certain it is the same issue . You do have a open recall for this very particular issue for my particular model . I love my car and GMC. Please remedy this situation and have me driving safely and free minded again and soon ! please reach back with any feedback as soon as possible. Thanks !.

My transmission keeps sticking when I shift into drive or reverse. Just a couple of days ago, it happened the worst it has ever done before. I shifted into reverse and my vehicle was completely stopped when I shifted. I began to let off of the brakes and gently push the accelerator to start moving back, my vehicle then punched itself into reverse. I felt after that incident, something had to have been damaged. I’m almost afraid to drive my vehicle after that. When my vehicle punched itself into reverse, I was literally jolted towards the steering wheel and thankfully my seatbelt caught me. Incidents with the the shifting into drive or reverse have happened before, but never nearly as intense. About a year ago, I brought my vehicle in to my local GMC dealership for a concern with my transmission shifting weirdly and holding itself in gear at an unnecessarily high rpm speed. The technician stated to me, “with these 9-speeds, they tend to get confused at various speeds”. I asked him to elaborate and he could not. These issues have now gotten worse. With my suspension, every turn I take, I get a kreaking sound from my front driver side wheel well. It sounds as if my tire if going to break off. I’ve done visual inspections and nothing out of the ordinary is noticeable to the eye. My vehicle is a 2019 with less than 40,000 miles on it. I should not be having all of these issues. I’m genuinely concerned for my safety.

Unintended acceleration in forward and reverse: the vehicle experiences unintended acceleration both in forward and reverse. While driving in heavy traffic, the vehicle continues to maintain throttle position for approximately two seconds after releasing the throttle, creating a dangerous situation where the vehicle continues to accelerate towards other cars. This defect requires emergency braking to prevent a collision. In reverse , the vehicle also holds throttle position after the accelerator is released. This results in the vehicle unintentionally accelerating in reverse at a rapid pace. This requires the driver to depress the brake moderately to control the reverse speed. During this event the driver is fighting against the motor with the brake pedal until the vehicle decided to stop accelerating on its own.

I hit a pot hole and a stabilitrack error popped up. Also reduced engine power I was miles from home and could have easily caused a major accident on the road.

See all problems of the 2013 GMC Terrain 🔎.

Was driving along and transmission downshifted (?) wouldn't change gears. Tachometer was like a race car. Just went wild. Limped it along to a dealership. They informed us it was probably the transmission. It was determined it was indeed the transmission. They also stated that they had 7 more waiting in the service area waiting for parts to repair. Ours was to be #8. We called the dealer we bought it from, they sent a tow truck and towed it to their service area. Luckily, I wasn't out on the interstate going 70 mph as I would have been in just a few more minutes. Very scary situation as I was in 3 lanes of traffic. It was in town, so traffic wasn't moving fast. I was 2 hours into my vacation. Needless to say, that put a damper on things. Had to rent a vehicle, unpack my vehicle and repack the rental. Oh, and by the was it is a 2024 Terrain with only 2400 miles!.

Purchased new from dealership 2024 GMC Terrain 4/2024. On 6/26/24 while driving the vehicle the transmission came apart and the vehicle suddenly stopped and would barely move off of the roadway. Had this happened 2 min prior while at highway speeds in crowded conditions, I can only imagine how many injuries could have occurred. My vehicle had 3800 miles on it. Upon my personal research, I found that this is a known problem with the 2024 GMC Terrains and dealerships across the country are filled with vehicles with the same problem. The dealership admitted to me that this has become "a known issue" and that they currently had 7 others with the same issue. They had my car for 8 weeks and according to my paperwork had to repair it twice as it failed the first repair road test! I filed a compaint with gm and was told "to not believe third party sites". I repeatedly asked why this wasn't a recall and they refused to answer the question. Does someone have to have their brand new transmission blow apart at 80 mph and take out others on the highway before they recall this? gm has issued multiple service bulletins to their dealerships but nothing to the public. I tried talking to the dealership and was belittled and stonewalled. Please recall these vehicles before someone is killed. I was finally given my vehicle back from the dealership today after 8 weeks because of no parts available. I am worried they repaired with the same parts that failed in the first place. I have the repair paperwork for your inspection if you would like to review it.

My daughter was driving her 2019 GMC Terrain at 15 - 20mph when she suddenly lost her brakes. Fortunately she had just turned into a new housing development where the road ended into an empty field. This could have been catastrophic for her & other citizens on the road. The following morning she would have been heading to work on a highway with heavy traffic with a posted speed limit of 65mph. We towed the vehicle home & after some investigating I found a vacuum pump failure. This vacuum pump broke apart internally sending chunks & shards of metal into her valve train. This issue is mentioned several times in Terrain forums & someone needs to address this issue before it becomes a fatality.

I was leaving work when my car had trouble accelerating from stop. The engine revved, but the gear would not engage. It happened several more times after I stopped at a light or slowed to get on the highway. It would take a minute or so to engage, and then I could drive the car, but it made it dangerous when trying to merge on to the highway or to make any turns in to traffic. It then happened two more times as I slowed to make turns until my engine light came on as I was turning on to my street. When I finally made it to my house and put it in reverse to back into my driveway, the car wouldn't move at all. I took it to the GMC dealership because it is still under warranty. The next day when I called, they told me a piston shot through the transmission housing which caused a leak of transmission fluid. There is a gm customer satisfaction program release for 2024 GMC Terrains and arcadias that all have a defect in the transmission housing, which is causing a leak of transmission fluid. I had noticed that, whenever I slowed to make a turn anywhere prior to the engine light coming on, there was some hesitation when trying to accelerate, but I thought it was the design of the transmission and engine.

Break booster pressure sensor and engine underbooster causes the car to slam on breaks or not break at all.

On 3 may 2024 my spouse was driving her new 2024 GMC Terrain in asheville, nc. When suddenly the car stopped and when was able to maintain control and coast to a safe area. The vehicle was subsequently taken to the dealers service center GMC asheville, nc (harry's on the hill). The diagnosis was determined to be a defective a transmission valve body. In discussion with the dealer service manager he indicated this is a common occurrence with the valve body. Needless to say this defect can be fatal especially during inclement weather, fast speeds, winding narrow mountains roads! as of 15 may 2024, the dealer, GMC nor the manufacturer of the valve body has not provided a replacement part for this vehicle.

My vehicle continues to slip and jerk out of gear , brought in to a local chevy dealership , they test drive the vehicle and acknowledge the issue. They updated transmission software and give it back to me to drive for 1000 miles or 30 days and see if the problem continues. Problem gets worse slipping and jerking more and more , made appointment dealership cancels my appointment saying they have no transmission tech come back next month for an appointment . Same thing no transmission tech available go somewhere else.

See all problems of the 2023 GMC Terrain 🔎.

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.

My check engine light comes on intermittently, since March 2024, after having cabin & engine air filters replaced. Each time, I’m told it is code p0171. This has happened too many times for my comfort. Usually, it happens around the time my gas gets below 1/2 tank or after I fill up my gas tank. Originally, I was told by the mechanic that it could be one of four things, of which I’ve now had some of things done. Inin Aug. 2024, the check engine light came in. Code was p0171. Mechanic replaced the brake vacuum pump. Once incident, almost a month later, on 9/24/24, was very scary. While driving on the interstate, I got ready to increase my speed, but heard a pop sound and noticed the speed wouldn’t accelerate. Next, the check engine light came on and the message in the dash popped up saying “engine power reduced” or something similar. I was able to coast from the fast lane over to the slower lane and off the highway into a parking lot. I turned the truck off. When I crunk it back up an hour later, it was shaking and jerking. While slowly driving, on the way to the mechanic shop, it jerked and shook each time I tried to accelerate after stopping at a light or slowing down with traffic. The code again was p0171. According to the mechanic, the intake hose had popped off. On 11/13/24, the check engine light came on. I again took it to have the code scanned and truck looked at. Test results again showed p0171. This time the mass air flow sensor was suggested. In a year I’ve had the fuel system cleaned twice, brake system flushed, & other routine maintenance such as oil change & brakes. Yet, my check engine light seems to still come on intermittently atleast once monthly. It came on two days ago, 2/18/25, when my gas was around 1/4 tank full. I added a fuel system injector, per mechanic suggestion, and filled my tank up with gas on today, 2/20/25. The check engine light had gone off within about 15 mins of me driving. I’m certain it will be back on soon with the same code.