Power Train Problems of GMC Sierra 1500 - part 1

Coolant control valve has failed and caused the check engine light to occur is available for inspection. Could cause the car to overheat and cause harm to myself or others yes has been confirmed by dealer no gm has a special coverage out for the specific vehicle and model years for this vehicle, but are stating that my vehicle does not pertain to that coverage.

See all problems of the 2021 GMC Sierra 1500 🔎.

Truck does not automatically shift into park when the door is opened. Getting out of my truck, I forgot to shift into park and opened the door, and the truck moved forward with automatically shifting into park, or applying the parking brake. I have a 2015 Jeep grand cherokee that did the same thing. There was a safety recall set forth by the NHTSA to have the car go into park when the door opened to prevent someone for being run over by the vehicle. My 2025 GMC sierra is experiencing the same issue. I was not harmed, but can definitely see someone getting hurt.

See all problems of the 2025 GMC Sierra 1500 🔎.

I’m scared to drive my vehicle because of the 6. 2l v8 ongoing engine failures! I believe it to be unsafe for travel never knowing when the engine will fail. Now with over 1 million failures of this engine!.

See all problems of the 2020 GMC Sierra 1500 🔎.

Shuddering, slipping, then lost all gears. Unable to put in reverse, drive, or low. Repair shop says the transmission needs replacement. Pump and torque converter issues. Vehicle has excellent maintenance and only 84k miles.

See all problems of the 2019 GMC Sierra 1500 🔎.

I bought the truck brand new from gregg young in atlantic, IA. While an hour into the drive home, the truck began shuttering as if the transmission was having problems finding the gear. I immediately made an appt with their parent dealership of gregg young in plattsmouth, ne. They had the truck for a week and couldn’t duplicate the transmission issues after I reported several occurrences and symptoms, they also didn’t provide a service invoice of the work performed while I found was unusual. As I was driving the truck home from repairs it started hesitating and having difficulty finding gears. I didn’t think much of it since the dealer claimed there was nothing wrong. This past weekend while going 65 mph down the freeway the transmission started shuttering as well as the truck and the tires began to lock up to the point of almost losing control, there was also metal on metal noises. I had to pull over and luckily driving real slow I made it home. The gregg young dealership were I bought it will take no responsibility and provided falsification since no service was provided nor upon checking app gps there was no indications it left the dealership while in there possession for a week, will contact GMC in the am since this has now become a safety issue and there was metal on metal contact noises and the serious risk of a crash.

While driving into work, I noticed a knocking sound from the outside of the vehicle. Once parked, upon further inspection I narrowed down the area of the noise to the bottom rear of the engine/front of transmission. Fortunately, I was able to park in front of my office building and wasn’t stranded on the side of the road but under different circumstances it could've been the side of a busy highway or hours from home. I had the vehicle towed to the dealership I originally purchased from, the dealership was able to duplicate the issue with me present. Later that afternoon I was informed that the engine had failed and a replacement would be ordered. There was no prior indication of a problem or warning/cel’s. The engine failed after the dealership had completed the engine recall ( pico test and 0-40w oil change ) related to the vehicle. I am reporting this in hopes that it helps with the investigation. This has been very disappointing for me as I have supported the brand of vehicle for many years. Only to have many issues under 80,000 miles and to lose confidence in the vehicle I purchased and the company.

I was driving down the road at 55 mph on 4/12/2026 and had let off the gas for a 45 mph zone when I experienced a violent downshift of the transmission that squealed the tires momentarily and felt like someone had hit me from behind. It startled me and caused me to lower my speed down to 20 mph. I continued driving to my destination and when I let off of the gas doing 45 mph for a slight curve I had another violent downshift that felt again like someone hit me from behind. I contacted a GMC dealer on 4/13. 2026 to see if there was a recall on the transmission that I wasn't seeing online and was told no. I described what I experienced to their service department and was told to flush out the transmission fluid and replace the filter. I did experience another bad downshift at a slower speed (about 25 mph) on 4/13/2026. There wasn't any warnings or lights that came on when these three incidents occurred. When looking online I did see there was a similar recall for 2020-2022 GMC sierra's where customers were experiencing similar violent transmission downshifts and am wondering if this issue is affecting more than just those three model years.

See all problems of the 2023 GMC Sierra 1500 🔎.

When I begin to accelerate on the highway, and the truck downshifts, it locks up the rear brakes.

See all problems of the 2024 GMC Sierra 1500 🔎.

Please append these work orders to this complaint number and VIN complaint: number xxx VIN: [xxx] three repair orders from beck & masten GMC south attached. Thank you!!! information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2022 GMC Sierra 1500 🔎.

The transmission has a shudder at various speeds.

2022 limited GMC sierra at4 1500 motor seized on highway with loss of propulsions on highway while towing an empty horse trailer. Truck had 64,000 miles. While driving it had lack of power and then flashed on dash to shift neutral and press start/stop button. Coasted to a stop on the side of the highway and shut truck off at which point it would not turn back on. Officer stopped to check as complaints about a truck partially on the side of the road. Had someone come to assist and try to diagnose. Had to tow truck off highway with trailer while officer followed behind with lights. Dropped truck off in empty lot unhooked trailer and left truck to be towed to dealer the next day. Dealership confirmed that day engine had failed under the l87 6. 2l v8 motor recall. Gave approx estimate of two weeks to fix. Currently at day 38 with no fix completed yet. Gm and dealer have both given run around blaming each other for the delay in providing a comperable "like" vehicle that can supplement towing needs broken truck was used for.

Engine failed at high speeds on interstate. When my truck shut off the steering and braking system went out and getting to shoulder of interstate was difficult with others around me. Express lanes were limited on emergency shoulder therefore my truck was partially on the high speed driving lane. 911 was called out to block freeway lane. Check engine light blinked right when truck shut down.

The motor on my 2026 GMC sierra stalled 2 weeks ago with a p0016(crankshaft position sensor issue). Was able to clear code and limp home. Vehicle did stall on a busy road and stop abruptly. Scheduled service and was advised to drive it in. Was experiencing irregular idle when warmed up, and a slight hesitation in the pedal. Service advisor started the vehicle and claimed no codes, and everything appear ok. Later in the afternoon the service advisor called to inform me that the vehicle had a siezed engine and had siezed during a test drive on the highway. Currently waiting on warranty information, and engine replacement information but I've been informed it will require a whole new engine. This is the same 6. 2l l87 v8 that has been in near constant recalls from GMC over the last 6 years.

Ticking at cold start. 4/02/26 on way home from work. Truck loses acceleration while driving. Bug jumps then display says low power mode. Truck will start but will not move forward or in reverse. Rpms increase but no propulsion. Recall was performed 11/17/25 and passed inspection through romain GMC evansville, in. Called romain on 4/02/26 and was told someone would return my call 4/03/26. Still waiting. Plan to call kate faupal dealership in henderson,ky on 4/06/26.

4/02/26 truck bug jumped hard and shifted down causing me to fishtail and almost hit a car. Scared the crap out of me and the driver of the other car. Low power mode. 20 mph. No reverse. Towed to dealership. Diagnosis valve body spacer. This is our first GMC. Barely had it over a year. 78k miles. No warning lamps prior to failure.

Engine lock up with 5018 miles on, it is a the 6. 2 motor rod and crank bad.

After owning this truck a little over a year I’ve had to replace the transmission and now it’s in the because the motor sounds like a bag of marbles was put in it and the warranty company is a joke they only want to replace just the cam and lifters but yet the dealership hasn’t be authorized to go to the bottom of the motor to check it out this truck has been nothing but a lemon!!!!!.

Transmission shudder and vibration at highway speed.

1- transmission issue, it’ll occasionally slip from 1-2 gear and engine rpm’s will shoot up making it when you release the gas pedal it’ll kick into second gear it’ll also do minor kicks into other gears (8l90 transmission) 2- breaks issue, unsure of what the problem is but at very low speeds like parking or going in slow traffic the break pedal will get really hard making you have to press extra hard for it to break, releasing and pressing again doesn’t help either.

See all problems of the 2016 GMC Sierra 1500 🔎.

While driving a "service transmission" message appears on the information center. The truck shifts slowly, sometimes slamming into gear, doesn't seem to have smooth acceleration through the gears until a high gear is reached. Unusual sounds occur during the shifting sequence. The vehicle was dropped off at the dealer for service. Dealer claims that since they were not able to duplicate the conditions reported to them, the vehicle was fine and not in need of any further investigation or service. Transmission problems are a known concern with vehicle as recalls have been expanded to include this class of truck in the recall but gm is not including this vehicle.

On March 13, 2026 I purchased a 2023 GMC sierra at4 pickup with 3. 0 diesel engine. While driving on a state highway in a 35 mph zone I started to accelerate as the speed zone changed. The truck suddenly had the rear wheel lock up for a brief time about quarter to half second then the truck proceeded on. This happened as the transmission was downshifting. Then on or about March 24, 2026 I was using the same truck and towing a 4,000 pound enclosed trailer. This trailer was hooked up within all recommended hookup requirements. In a 225 mile trip I experienced the same rear wheel lock up happen 4 random times during the trip. Once this happened at 65 miles and hour had there been snow or ice on the highway the truck may have crashed. This lock up happened while using the truck in tow haul mode. Two times it happened while the truck was being towed with cruise control active and two times it happened while not using cruise control. Truck was brought to authorized gm dealer and inspected and truck had no stored codes from transmission related issues. Dealer blamed this for using cruise while towing. I informed dealer this happened while not using cruise as well. Was told to turn off adaptive cruise when towing. I was unable to find anything in the GMC manual regarding not using cruise while towing. This appears to be an issue with the valve body in the transmission and customer explained this to the dealer but they denied this claim. When these quick moment lockups happen no codes or engine lights show everything on dash appears normal. Customer is bringing truck to another gm dealer to be tested and examined.

The contact owns a 2019 GMC Sierra 1500. The contact stated that while stopped, there was an abnormally loud sound coming from the vehicle. The vehicle was consuming an excessive amount of engine oil. The engine and transmission warning lights were illuminated. The vehicle was initially taken to the local dealer; however, the dealer was unable to determine the cause of the failure. The vehicle was later diagnosed, and it was determined that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the issue and referred the contact to the NHTSA hotline for assistance. The failure mileage was approximately 106,000.

Engine seized.

While driving at approximately 60 mph on an open road with no obstacles present and no braking input, the rear wheels spontaneously locked up without warning. No brake pedal input. No warning light prior to the event. No obstruction in the road. The vehicle has been subject to an active manufacturer recall for rear wheel lockup due to transmission control valve failure. The dealer's own diagnostic system generated a report showing six active fault codes in the following days including lost communication with the brake system control module and transmission control module. These codes were not addressed on the repair order. The dealer attributed the lockup to an automatic emergency braking activation without diagnostic confirmation and performed no repair. The manufacturer's own internal bulletin dated January 22, 2026 acknowledges the exact fault codes present on this vehicle as a known defect. The dealer cited this bulletin to dismiss the concern while stating no problems exist. A persistent brake noise has been confirmed by two separate authorized dealers across three visits with no repair performed at any visit. The vehicle has required five dealer visits in 77 days of ownership with 1,729 miles. The defect remains unresolved and poses serious risk of loss of vehicle control at highway speed.

While driving west on hwy 20, near augusta, GA my vehicle motor blew without any warning. I had to guide my dead but rolling truck and trailer to the side of the hwy against a high retaining wall. The truck shut down and set the brakes after stopping and would not restart, shift into neutral, or move without special two equipment. **when I received the first recall notice I call my GMC dealer and they said their was nothing they could do yet. Later I received a second notice and responded to GMC dealer where the changed the oil and cap. A few weeks/months after that the motor blew. Gm has refused to be any help and replacement motor has been on back order for 3 weeks and counting.

The contact owns a 2022 GMC sierra denali 1500. The contact stated that while driving at 73 mph the vehicle lost motive power. The contact was able to pull over safely. The driver was unaware of any warning lights being illuminated. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not notified. The failure mileage was unknown. The VIN was not available.

My 2023 GMC sierra has 60,571 miles for a while now while driving the transmission slips and slams into gears. Recently driving with my kids in the car on highway going 70mph the back brakes locked up multiple times, so scary and dangerous while driving. I now currently have a code p-0747 in the system.

While driving down the highway experienced a partial loss of engine power causing jerky/rough operation, harsh shifting, and unpredictable behavior. Was told by the dealer service manager that it was likely a misfire in one of the cylinders. After diagnostics and servicing that included changing spark plugs, wires, and a full engine service it was later confirmed to most likely be due to a stuck lifter and will require a complete engine replacement. I have subsequently learned that this is a common problem with this l87 engine and may be an early indicator of failing crank bearings associated with a recall for later model years of my same vehicle. Seems to me that recall ought to be expanded to include earlier models with l87 engines.

With the cruise set at 55-60 mph the rpms will jump, along with a slight shudder feeling. Cruise control has turned off a few times due to this. Cruise set at 25mph and would shudder/lunge forward. Torque converter is showing it’s slipping and will need replaced. No check engine lights.

Vehicle experienced a catastrophic mechanical failure characterized by a percussive "shotgun blast" noise from the rear chassis, followed by an immediate, total loss of braking power (pedal to the floor) and a violent loss of directional stability. This incident represents an aggravated safety failure of known gmt900 platform defects. The technical chain of causality began with the factory exhaust manifold fasteners suffering a metallurgical shear, a universal defect documented under gm bulletins 19-na-218, pip5075, and pip4701. This shear created a high-velocity, high-heat exhaust leak directed at the brake master cylinder and vacuum assembly. This "heat soak" event compromised the engine-mounted mechanical brake vacuum pump (recall n192268490 / NHTSA 19v645) and destroyed the internal seals of the master cylinder (special coverage 15143 / NHTSA 11v599), resulting in total depletion of vacuum assist and hydraulic pressure. Simultaneously, the "shotgun blast" and violent swerve were caused by structural failure consistent with rear brake caliper bolt fracture (gm 13247 / NHTSA 13v342) and rear axle shaft/pin fracture (gm 14892 / NHTSA 14v819). This mechanical collapse caused the caliper to strike the wheel, resulting in a catastrophic rim blowout and immediate loss of tire pressure. Despite the vehicle having aftermarket long-tube headers installed, the root cause of the heat-related brake failure was the failure of the oem gm manifold fasteners which snapped off in the cylinder head, as documented in the aforementioned bulletins. Under the magnuson-moss warranty act, the manufacturer remains liable for these pre-existing safety-critical defects. The vehicle is at glenn polk Chevrolet for a 901-series product allegation investigation (case #90199492). This report is filed to demand federal oversight into these life-threatening defects. The combo of failed fasteners, rim blowout, and compromised braking created a vehicle that was both unable to be steered or stopped.

See all problems of the 2011 GMC Sierra 1500 🔎.

Per GMC dealership, this vehicle suffered a transmission valve body failure and they are recommending replacement of the entire transmission.

Motor was replaced at 70000 miles it blew rear main on the technician. Now 30000 miles later saying it needs valve body its been in shop 5 weeks now and no eta on parts. Also the onstar module went out or never worked after engine replaced. The truck has locked up 4 times before the engine was replaced once at 11000 miles. Had hard shifting issues from new dealership kept saying it just needed an update or tuned everytime until 100000 miles warranty was up. On my truck all the extras were were installed when they arrived. Heated and cooled seats. Heated steering wheel, park assist and something else however the truck was already out of manufacturers warranty before the 1st item installed at 50000 miles over a year after I had purchased. Everytime something was put on something else failed. And the grille started peeling immediately after I purchased vehicle and is almost completely gone.

My 2024 GMC Sierra 1500's engine has gone bad, and needs to be replace after only 71,000 miles, and this is only 90 day after already replacing the transmission.

On 2/23/26 my GMC Sierra 1500 at4 3. 0l inline-6 turbo-diesel, it auto stopped (which I will never keep on again) on an incline and would not start back up or shift gears and rolled a few feet. I had to turn it off and restart it, then the engine light came on and a notification about conditions not favorable for shifting? my app said service was needed for engine/transmission issue. I took it to the dealership and it now has to have the transmission control valve body assembly replaced. I did not receive a recall notice for my truck but, it seems to be the same issue that the recall was for on gm vehicles of the same time period. Of course the dealership said they have no loaner vehicles and I'm supposed to be without my truck for approx. A week and a half at this point. I am disappointed with GMC and the quality that I am paying $70k for. I had a 07' silverado 2500 I purchased new and drove it for almost 15yrs. W/ no issues. Hopefully this is a good fix and it'll last but, from what I've seen, gm is not the quality it used to be. This is on top of being in the shop for a coolant control valve issue that wasn't recalled either but, a known issue on the pickups so beware. I did call GMC and they will reimburse up to $44 a day on a rental (has to be a gm vehicle btw) during this fiasco of course afterwards and with a bunch of paperwork but, I have to have a vehicle, in TX nothing is close by. Good luck everyone!.

My engine seized up on me on the highway. I was stranded and couldn’t start the vehicle and it was freezing outside.