Engine And Engine Cooling Problems of GMC Terrain - part 1

Since purchase, this vehicle has consistently had an issue with the fuel system. When I call GMC they state only use no ethanol fuel. I wouldn’t have bought this car if that was the case. The dealership never said that when I was buying it. We replaced the entire engine for $11,000 because of a torn radiator hose, overheating and cracked a gasket. Now, the car is refusing to drive, giving engine power reduced.

See all problems of the 2024 GMC Terrain 🔎.

Accelerator lag from any speed or stop. The care will take several seconds to hunt for the correct gear before shifting to accelerate. Or it will delay acceleration for several seconds while your pressing the accelerator. No ses indicator active. Mechanics can’t find issues. Other owners on forum a report the same sluggish behavior. These 1. 5 turbo cars seem to need a software fix that they are not receiving. It’s like the drive by wire doesn’t register. Affects any gm vehicle with the 1. 5 turbo and 9 spd auto.

The contact owns a 2022 GMC Terrain. The contact stated that while his wife was driving 35 mph, the contact received an email and text from onstar with dtc: p129f, and the message to not drive the vehicle was displayed. The check engine warning light was illuminated. The vehicle was taken to the local dealer, where it was diagnosed and determined that the fuel pump power control module had failed. The vehicle was repaired, but the failure reoccurred. The contact stated that the failure was related to n252516900, a general motors (gm) emission recall related to the fuel pump power control module (fpcm and gm safety recall n222372310 – inadequate fuel pump flow. The local dealer was contacted, who stated that the fuel pump had failed to meet higher outputs. The manufacturer was contacted and confirmed that there was no coverage on the vehicle. The failure mileage was approximately 66,000.

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On June 7, 2026, I was driving my 2020 GMC Terrain. I was going at about 40mph along a very busy main road. While slowing for a red light the check engine light turned on and the car displayed a notice about reduced engine power. Seconds later, the brake pedal became stuck and would not press down all the way and I lost braking ability. The car rattled/shook violently, made a grinding noise, and then the engine shut off and the car stopped abruptly, narrowly avoiding hitting the car in front of us. I turned on the hazard lights. I was not able to get the car to start again, nor was I able to get the car to shift into any other gear including neutral. We were nearly hit by other vehicles multiple times while attempting to get the car to move again, and to get myself and my child safely out of the road. Myself and multiple bystanders attempted to engage the transmission interlock override multiple time. We were eventually able to engage it and push the car to the side of the road. This failure created an extremely unsafe situation for all involved as this road is very busy and there were numerous near-collisions both with my disabled vehicle, and with other drivers serving out of the way and into other lanes at the last second. As time went on and the battery drained, most of the car's exterior lights turned off and other drivers had a hard time seeing my car. I used a strobe flashlight to alert other drivers but this required that I had to stand in the road near the vehicle. Police were called immediately when I found that we could not move the car out of the road, but they did not arrive. Ultimately the vehicle was stuck and inoperable in a travel lane for over two hours. The car was then towed to a nearby repair shop. The mechanic evaluation stated that the brake vacuum pump had failed resulting in loss of braking ability and expensive damage to the engine and other components. The manufacturer is aware of this issue. See: thieme, et al. V. General motors llc.

See all problems of the 2020 GMC Terrain 🔎.

During my daily commute to work on the interstate the service break assist message came on my dash and when attempting to break the pedal was very hard, to the point where I had to push extremely hard and quickly realized I had to brake much much soon than normal to prevent hitting other vehicles. Sudden loss of brakes put me and other drivers at risk due to my near inability to slow down or stop and the sudden and unexpected nature of the event.

I am a [xxx] resident. While commuting to work in [xxx], my GMC Terrain experienced a sudden, catastrophic failure of the brake vacuum pump while traveling at highway speeds. When I attempted to slow down for the exit, the brake pedal instantly became extremely stiff and nearly impossible to depress. I realized I had suffered an absolute loss of power braking assist. To avoid a high-speed collision with heavy highway traffic, I was forced to deliberately steer onto the roadside rumble strips, relying on tire friction to slow the vehicle down. This severe near-miss left me terrified and distraught. Because the shoulder was narrow, my disabled vehicle was left partially protruding into the active roadway. Passing cars sped by so close that my vehicle was violently rocking, creating an incredibly unsafe situation. I was forced to call the state police for emergency assistance. They dispatched a trooper and a tow truck to remove me and the vehicle safely from the highway. The vehicle was towed to a mechanic in massachusetts. The mechanic discovered that the vacuum pump had internally exploded. This explosion sent catastrophic metal shards and debris directly into the engines oil galleys and oiling system. While the vehicle has 121,776 miles, this is not a normal wear-and-tear component failure. The brake vacuum pump suffered a catastrophic internal mechanical explosion at highway speeds, completely eliminating my ability to stop the vehicle. A mechanical component failure should never cause an immediate, life-threatening loss of brake control, regardless of mileage. This is a known, systemic engineering defect that is currently the subject of active federal class-action litigation (xxx v. General motors llc). This defect did not just cause an immediate life-threatening braking failure, it completely contaminated the oiling system, destroyed the entire engine, and rendered the vehicle a total loss requiring a full engine replacement. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552.

My car has started stalling and dying when I slow down, take off or when idling. No power when accelerated, and the smell of exhaust comes into my car. I was making a turn from a red light and my car spit, sputtered, and died right in the middle of the busy intersection. I was almost hit from the rear and another car had to go into on coming traffic to avoid t boning me. I took it to 2 different places to get a diagnosis reading and both places said it was a catalyst problem, and I was told that there was a recall about that because of engine oil clogging it up. My car has been using more oil than usual here lately and im guessing thats why. Now, im afraid to drive anywhere because I don't feel like it safe and the fact that my car doesn't run good enough to drive. I was told by more than 1 person that knows mechanics, that its a issue with the catalyst and that it had a recall on it but I never received one. This is a very concerning safety issue, and one that needs immediate attention before someone gets badly hurt (or worse) because of a bad car part . My car is literally just a lawn ornament now until I can get this issue resolved. I need my car to make a living and support my family. Please, get the recall letters out and get this fixed before someone loses a life.

See all problems of the 2012 GMC Terrain 🔎.

Transmission wouldnt shift. Sensor in car is causing issue, code is n 202321840.

I am submitting this complaint regarding a serious and dangerous brake failure involving my 2020 GMC Terrain slt with approximately 150,000 miles. While driving, the vehicle suddenly experienced a vacuum pump failure that caused a severe loss of braking ability with no warning beforehand. The brake pedal became extremely hard, and the vehicle would barely stop. This created a very dangerous situation and could have easily resulted in a serious accident. Thankfully, I was not driving at a high speed when the failure occurred, and there were no vehicles directly in front of me at the time. However, only minutes earlier I had been traveling approximately 65–70 mph on the highway. If this brake failure had occurred while driving at highway speeds or in heavy traffic, I truly believe it could have caused a major crash resulting in serious injury or death. What concerns me most is that there was no warning before the brakes failed. No warning lights and no issues with my brakes. The sudden loss of braking power was extremely frightening and created an immediate safety hazard. After researching this issue, I discovered that other GMC and gm vehicle owners have reported similar vacuum pump failures and brake assist problems. I believe this is a significant safety issue that should be investigated further. Drivers should not experience sudden brake failure without warning, especially on a vehicle that otherwise appeared to be operating normally beforehand. I am very thankful no one was injured in my situation, but I am concerned that another driver may not be as fortunate. My vehicle had to be towed to a nearby shop and they suspected it was the vacuum pump failure and the car started smoking badly. So I had it towed to the GMC dealership and they called me today to confirm that was the problem and it also caused damage to the camshaft. This is a known issue with the Terrain and there is currently a class action lawsuit.

I have had 2 different instances where my vehicle stops in the middle of a busy intersection or traffic and have no warning what so ever. Vehicle just shuts off and I am not able to turn back on to move out of the way. First time I got it repaired it was related to the fuel pump and now I am waiting to hear back from my mechanic to see what the issue is but so far it is an indication of the fuel pump as well. Both times I required help from law enforcement because vehicle shut off in the middle of the road and safety to myself and other drivers was an issue until tow truck arrived to move my vehicle.

See all problems of the 2023 GMC Terrain 🔎.

The contact owns a 2019 GMC Terrain. The contact stated that while stopped and attempting to turn to exit a highway ramp, he observed a loud banging noise emanating from the engine compartment. An "engine reduced power" message appeared. The vehicle then went into limp mode, and when the brake pedal was depressed, it was stiff as a rock. The vehicle coasted while he continued attempting to depress the brake pedal, and it eventually slowed down. The vehicle was steered to the side of the road and turned off. When the vehicle was turned back on and he attempted to depress the accelerator pedal, the vehicle did not accelerate. The vehicle was taken to his mother's residence approximately 100 miles away in limp mode and parked. The vehicle was not diagnosed or repaired. The contact stated that his brother, during an inspection of the vehicle, removed the vacuum pump and noticed that it was broken with numerous pieces that had gone into the engine. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 76,000.

See all problems of the 2019 GMC Terrain 🔎.

My 2016 GMC Terrain 2. 4l ecotec first stalled while idling at a red light in raleigh, nc. I restarted it and it sounded different, so I drove it home. The next morning it would not start. The failure occurred at approximately 69,939 miles with no meaningful warning. The dealer’s diagnostic report states there were no current relevant codes and no relevant codes in history. The dealer documented major timing-system failure: timing chain tensioner failure, timing chain guide failure, a timing chain guide bolt pulled out of the cylinder head, aluminum contamination in the cylinder head/oiling system, and engine replacement recommended. The vehicle was found unsafe to operate. This vehicle regularly transported my family, including my children. If the stall/no-start failure had occurred at highway speed, while merging, or in heavier traffic, it could have created a serious crash risk. The oil was maintained outside the dealership network and had been serviced before failure. I also topped off the oil shortly before this occurred. The 2. 4l ecotec engine family is known for oil-consumption issues, yet this vehicle gave me no direct warning that oil consumption had reached a dangerous level. A reasonable owner would not know to check oil every day when there were no relevant stored warning codes. Other NHTSA complaints involving 2016 GMC Terrain vehicles describe similar patterns: oil consumption, no warning lights, sudden stalling or no-start conditions, timing-chain failure, and engine replacement recommendations. I am filing because this appears to be an ongoing safety risk involving oil consumption without adequate warning, timing-chain/timing-guide failure, internal contamination, and sudden engine failure. I request NHTSA review this issue for investigation or recall expansion before this failure mode causes a preventable serious crash, injury, or fatality. The vehicle was inspected by a GMC dealer and remains unrepaired.

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After vehicle acting like it isnt getting power and trying to die, I pulled into a gas station and turned it off. When I went to restart it, the vehicle kept turning over and over automatically not wanting to start and the engine light came on. I let it sit for about 5 minutes and tried again. It did same thing. I tried a 3rd time pushing the gas pedal and it finally started. I made it home 2 miles away. Turned the car off and tried starting it again with same issues.

I bought this car and the mileage said 120k, but the title says when it was tagged 157k. The car has been tampered with and the some of the lights for the car on the dash are missing, such as the check engine light. Also, it misses so bad that it will die at times.

See all problems of the 2010 GMC Terrain 🔎.

Took dealer 3/26 for sam issue engine power reduced after already cause me hit curb. Got it out 4/1/26 now 4/5/26 it happened again same codes after they claimed they fixed it. Also keep having emergency services come on a caused my dashboard out. My issues is car keeps stalling losing power. Same codes as week ago after dealer fix. Also 4 time took for noises in my car from passenger side. They keep telling me they can’t replicate it, but you can clearly see where the door is not lined up. This has been going on for over 30,000 miles for that. Like some of these issues have been going on since the 36,000 but now I’m having issues where I’m losing power like this is insane all before 60,000 miles which I’m about to hit. It’s gonna end up getting me killed on the interstate. My VIN also says it’s fwd it’s awd at4 . Called dealer said only to update software clearly not the issue. My doors are off and they have refused to fix those for over 30,000 miles now. It won’t let me attach any pics for some reason I’ve tried since yesterday.

Oil consumption, causing high pressure furl pump to clog. It also causes catalytic converter to clog. No warning of oil loss. Causing stalling out while driving. Caused the engine to seize. New engine replaced and still same problem s.

See all problems of the 2015 GMC Terrain 🔎.

Have had to replace the vvt solenoids several times within a year spam. Had to replace the rear main seal because it blew out due to carbon build up. Having issues with excessive oil consumption. Now the vehicle just started with: going from a stop position to accelerating at low speeds the vehicle stalls and dies. I want gm to take accountability and fix this issue as it is a safety issue to myself and everyone on the road.

See all problems of the 2017 GMC Terrain 🔎.

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.

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Vacuum pump exploded into camshaft and engine area, causing me to lose brakes completely on the highway. Costly repairs to clear out metal shrapnel and replace camshaft.

The contact owns a 2023 GMC Terrain. The contact stated that while driving on several occasions at various speeds, the check engine warning light illuminated, the message "engine power reduced" was displayed, and the vehicle lost power. The vehicle stalled on three separate occasions. The vehicle was able to restart each time after approximately 15 minutes of waiting, but the vehicle failed to accelerate above 40 mph. The vehicle was taken to a dealer and dtc: p228c, p0089, and p006c were retrieved, and the contact was informed that the fuel pump and fuel injectors needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was unknown.

I was driving 55 miles an hour on an expressway. And suddenly my truck just shut off. The brake became very hard unable to break very scary situation for me and my children. Engine power was reduced and would not start, many errors came up. The vacuum pump failed, which also caused the cam shafts to fail. The vacuum pump exploded into pieces and sent metal into my engine.

The turbo went completely out at around 105k miles while I was driving to work. I had to coast into a repair shop because it was smoking and wouldn’t go over 20mph and then have it towed to the place that repaired it. Since then, the transmission is having trouble shifting gears. The car struggles to accelerate and I have to go abnormally slow after coming to a complete stop in order for the car to get into gear. The onstar diagnostic says everything is fine but it is clearly not fine.

My vehicle started turning off suddenly when stopped and then when starting to move. I replaced my rear seal. A week later, I have oil in my timing and my engine no longer works. I have had it checked by a shop. No warning was given. I have my oil checked regularly and changed on time. I had a car full of people, adults and children, in rush hour traffic. The car is sitting in my driveway as I will need to negotiate with the lender on money owed. I am currently without a safe vehicle to drive, and I need that as I am a caregiver and home aid.

Check engine light is coming on, indicating reduced engine power. Took vehicle to GMC dealer and they advised that the repair shop was getting assistance from the GMC tech line to update a module to correct the issues. I was informed today that the high pressure fuel pump will have to be replaced, along with a hose or pipe to correct the issue. The vehicle has 57k miles on it. Upon researching the issue, I found that this has been a persistent issue with this model vehicle, dating back to 2020. It appears that it has not been resolved and the vehicles could stall or stop at any time. There is currently a class action lawsuit pending on this issue. Please help, this is dangerous.

While driving several times smelt gas and car cut out engine came on and car stopped mid driving multiple times. Says they replaced fuel pump reset car etc.

I was driving the car on 12-22-25 I lost power my car died on i94. Battery died the dearlship couldnt get the code. Got the car back on 12-26-25. Engine light came on carrie GMC replaced battery . Car back on 12-29-25. . Engine light back on 12-31-25 car back on 1-8-26 replacled catalytic conveerted and oxy sensor. 2-20-26 driving on 1-94 lost engine power car back on 2-25 feul pump and feul line. Drove 300 miles engine light back on. Back to currie GMC on 2-26-26 untill 3-2-26 replacred heated oxygen sensor . 3-6-26 replaced catelytic converter and oxyger sensor for the second time.

Brakes were hard to engage or press when stopping due to vacuum pump stop working. Had to replace the vacuum pump.

The contact owns a 2017 GMC Terrain. The contact stated that after the vehicle was taken to a local car wash, while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to the residence; however, the next day, the vehicle hesitated while starting. The message "stabilizer - power to engine reduced" was displayed. The vehicle was taken to a local independent mechanic, where it was diagnosed, and it was determined that the engine possibly needed to be replaced because the engine failed to turn over. The vehicle was towed to a local dealer, where it was diagnosed, and it was determined that the engine was blown. The contact was informed that the engine and the starter needed to be replaced. The vehicle was not repaired due to the cost and remained with the local dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 104,750. The VIN was not available.

My husband just did an at home oil change on the car not long before the incident. Unfortunately my car was barely under 3,000 miles since the oil change and we were going to change the oil again when my engine died mid drive on the way home. There was no oil in the car due to high oil consumption and no coolant either. High oil consumption was not reported and not disclosed to me before and a broken guide for my timing chain leading to total engine failure just after I started to exit the highway. Had my car died any sooner I would have crashed. Or wrecked with another vehicle. GMC and the dealership I got the car from did not properly disclose this safety risk to me when I purchased the car and no recall information was ever sent out. The high oil consumption causing engine failure has been a part of a class action lawsuit for these vehicles before and that was not disclosed to me either at any point. No notifications of low oil or other issues aside from a check engine light came on for my vehicle when I was driving. I dont know how fast I was going as I was applying the brakes to my car for a traffic light.

See all problems of the 2014 GMC Terrain 🔎.

On febuary 14 2026 I was driving on the feeder of the freeway with speeds of 50 mph my car suddenly down shifted in the middle of driving started shaking real bad stalled wouldn’t start wouldn’t go in gear at all would just die and say engine power reduced. This is after it had just been at the dealership and they said all I needed was an update. It had to be towed and the dealership said it was my high pressure fuel pump had failed. They replaced it and gave me the car back. I staled the next morning going to work on the freeway going 70 mph same exact thing happened except this time I could smell gas so strongly. I had to sit on the side of the highway until it was picked up due to gas smell and fear of fire. They say a bolt broke off of the high pressure fuel pump they just installed.

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.

See all problems of the 2021 GMC Terrain 🔎.

I am driving a 2019 GMC Terrain slt, and I have a serious concern regarding a recent service experience. On 02/10/2026, I had an oil change and a complete vehicle inspection performed at kunes GMC greenfield, wisconsin. After the service was completed and I returned home, I noticed an unusual noise coming from under the engine hood. I immediately went back to the dealership and informed them of the issue. I was asked to return the following day (02/11) for further inspection. After their investigation, I was informed that the vacuum booster had failed. It appears that this issue was not identified during the original inspection, and I was the one who brought the noise to their attention. From my understanding, vacuum pump/booster issues are common with many 2019 GMC Terrain models. I am surprised that this has not resulted in a recall, especially considering the potential safety risks it poses to me and my family. What concerns me even more is that this issue was not detected during the dealership’s inspection. If it had worsened, it could have led to a serious safety situation. I had to spend $450 today to repair what appears to be a manufacturing-related defect. I respectfully request that this matter be escalated and that my claim for reimbursement be reviewed. I would appreciate your assistance in helping me pursue compensation for this expense.

I had a message flash that said the power to the engine was reduce. Next message said check stabilink ( or something similar). . It said drive with caution. I live 2 mins from my job I drove home and pulled in the driveway I then felt the car act like it wanted to shake. This was on 2-10-26 I contacted onstar asked them to run a diagnostic. The codes that came back p0016 p0089 p228d are very well known codes with many people with the same vehicle/engine that have had to replace the engine. The engines have known issues had I known that maybe I could have replaced a part or two or three or four to have a stable vehicle now my vehicle is currently at GMC dealer since Tuesday morning actually had it towed there Monday night. I called Wednesday evening they still wasn't sure the "issue". Thursday I wait until about 1pm spoke with john he said well we are pretty sure you need a new engine the mechanic is checking a few more things the car has no pressure. About a hr later I get a email and a call saying the timing chain skipped and something about the pistons and the valves and I need a new engine . John called me and said well. Ill tell you what we will offer you a brand new engine for the same price as a rebuild plus you get 3yrs 300 thousand warranty for 10,944. Give or take a few dollars. We'll first I paid like 15,500 for the car that I just litetally paid off like Jan 12026. I really feel like had GMC made buyers aware that the vehicle has defective parts/engines buyers could replace parts or GMC should be held accountable. I started googling the engine and found out that there is a class action lawsuit and a recall on " certain" 2017 Terrains depending on the VIN. Same issues my car is having but its saying my car has no recall.

Rear main seal blow out.

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.