2019 GMC Sierra 1500 transmission problems

POWER TRAIN

The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed and the vehicle started jerking and shaking before unintendedly accelerating. Additionally, the vehicle jerked and started to lose motive power. The dealer was contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 108,000.

NHTSA complaint #11758287 — an unverified report by a vehicle owner.

POWER TRAIN

At approximately 85,000 miles, the engine in my 2019 GMC Sierra 1500 seized. The vehicle was parked when it occurred. This created a safety risk because an engine seizure can cause sudden loss of propulsion in traffic. Before the failure, I didn't notice anything that would raise any alarms. The problem was inspected and confirmed by a GMC dealer, which diagnosed the condition as an engine seizure. The failed engine is not available for inspection. I am not aware of the precise internal cause beyond the dealer’s diagnosis.

NHTSA complaint #11756621 — an unverified report by a vehicle owner.

POWER TRAIN

At approximately 85,000 miles, the engine in my 2019 GMC Sierra 1500 seized. The vehicle was parked when it occurred. Inability to start. This created a safety risk because an engine seizure can cause sudden loss of propulsion in traffic. Before the failure, I did not notice any red flags. The problem was inspected and confirmed by a GMC dealer, which diagnosed the condition as an engine seizure. The failed engine is not available for inspection. I am not aware of the precise internal cause beyond the dealer’s diagnosis.

NHTSA complaint #11756622 — an unverified report by a vehicle owner.

POWER TRAIN

The contact owns a 2019 GMC Sierra 1500. The contact stated that while at a red traffic light, the vehicle accelerated unintendedly, and the vehicle shuddered with an abnormal dinging sound coming from the vehicle. The message "Transmission Hot - Idle Engine" was displayed on the instrument panel. The vehicle was taken to a dealer where it was diagnosed and determined that the transmission was slipping, overheating, and that the transmission needed to be replaced. The contact researched and became aware of a recall; however, the VIN was not under recall. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 126,098.

NHTSA complaint #11756219 — an unverified report by a vehicle owner.

POWER TRAIN

Subject: Event of engine failure • While driving on a level paved road at 15 miles per hour in a busy area my 2019 GMC Sierra Denali pickup truck stalled in the middle of a busy street. • Truck stalled in a heavy traffic area at an intersection putting myself and passengers in a dangerous area and situation. This obstructed the normal flow of traffic causing a danger to pedestrians and normal vehicle traffic pattern. Each had to go around my disabled truck into oncoming traffic putting them and normal traffic flow at risk. •Upon securing a towing service the truck was transported to the nearest GM dealership. This happened on a Friday afternoon and the truck got to the dealership after hours. I returned to the dealership the next morning and was told that they may not be able to check the truck until probably Tuesday. On Monday afternoon I called and they hadn't been able to get to it. I received a call the next day and was informed that the technician at the dealership had put a breaker bar to the crankcase and the engine would not move and therefore the engine is seized. • There were no warning lights that came on prior to the truck stalling in the street. There was no noise prior or any other symptom to give any indication that the truck was not operating in a normal fashion.

NHTSA complaint #11753006 — an unverified report by a vehicle owner.

POWER TRAIN

TSB 19-NA-121. My truck is experiencing the exact issues detailed in the listed TSB. Randomly and quite often my truck feels like I am running over speed bumps. This just started about 3 days ago. The truck has been maintained. Oil is changed on time and there was a 100,000 mile service and I just had a 150,000 service done. Currently there are roughly $148,000 miles on the vehicle. Is there a way to have GM cover the costs of the repairs even though my VIN# was not listed. Also I am experiencing sudden power loss which is also mentioned in other bulletins. Basically it feels like the engine hesitates to accelerate.

NHTSA complaint #11750497 — an unverified report by a vehicle owner.

POWER TRAIN

Experienced the GMC shudder while driving on the highway. This is a known issue with GMC transmissions valve bodies and torque converters. I would like to know why my vehicle is not on the recall list 2019 GMC? 85,000 miles and has always shifted hard randomly when cold but was unaware of the problem until this shudder became an issue and started looking into it.

NHTSA complaint #11750384 — an unverified report by a vehicle owner.

POWER TRAIN

The engine went into limp mode as I made turn leaving the damn I was is in town and it was a lot of traffic could’ve been bad if I didn’t pull into the median left me devastated and no crank no start I’ve only had the truck a year it went down a month from when I purchased it

NHTSA complaint #11750178 — an unverified report by a vehicle owner.

POWER TRAIN

I am writing to formally log a safety concern regarding my vehicle’s 6.2L L87 engine, specifically in relation to the known defects under NHTSA’s ongoing Engineering Analysis EA25007 (previously Preliminary Evaluation PE24004).While my vehicle is currently running and has 52,000 miles on the odometer, it falls squarely within the manufacturing window being investigated for premature engine failures due to defective connecting rod bearings and Dynamic Fuel Management (DFM) lifters.My primary concern is the severe safety hazard presented by a sudden, catastrophic engine failure. A sudden seizure or loss of motive power at highway speeds puts myself, my passengers, and other drivers at an immediate risk of a high-speed collision, especially if it occurs without prior warning lights or symptoms.Because GM’s previous engine recalls (such as 24V-418) excluded the 2019 model year despite utilizing the same vulnerable engine family, I am filing this report to urge the NHTSA to expand the recall to include 2019 models. I want my vehicle's VIN documented as part of this vulnerable population so that a proactive, permanent remedy can be mandated before a dangerous highway failure occurs.

NHTSA complaint #11749489 — an unverified report by a vehicle owner.

POWER TRAIN

Transmission blew on a 7 year old vehicle. Was replaced entirely and is NOW having the EXACT SAME PROBLEM AGAIN!

NHTSA complaint #11741983 — an unverified report by a vehicle owner.

POWER TRAIN

While driving, the vehicle suddenly began running rough, losing power, and displaying engine warning lights. Due to the severity of the issue, the vehicle was towed to a GMC dealership for diagnosis. The dealership diagnosed lifter failure and a cracked cylinder head. The dealership also documented coolant intrusion, oil/coolant contamination, and evidence of internal engine damage. Repairs were attempted, including replacement of the cylinder head and lifter. After the repairs were completed, the vehicle never left the dealership because it continued misfiring on the same cylinder. GM later determined the engine had a failed piston ring and scored engine block requiring complete engine replacement. The vehicle has approximately 55,000 miles, has been properly maintained, and was purchased new. This catastrophic engine failure resulted in loss of power and major internal engine damage at relatively low mileage. I also opened a case directly with GM Customer Assistance regarding this failure. The case involved multiple escalations after the initial repair attempt failed and the vehicle ultimately required full engine replacement. GM ultimately advised that only partial assistance toward the engine replacement would be provided, leaving the customer responsible for a significant portion of the repair cost. I am submitting this complaint because this vehicle appears consistent with the ongoing NHTSA investigation involving GM 6.2L L87 engine failures and loss of motive power.

NHTSA complaint #11740464 — an unverified report by a vehicle owner.

POWER TRAIN

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.

NHTSA complaint #11733059 — an unverified report by a vehicle owner.

POWER TRAIN

The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving approximately 5 MPH, the rear wheels locked up. The check engine warning light was illuminated. The vehicle was taken to a local dealer, where it was diagnosed, and determined that the brakes needed to be replaced. The vehicle was repaired; however, the failure recurred intermittently. The vehicle was taken to another local dealer, Walker Bros Chevrolet (700 Erie St, Edinboro, PA 16412); for a second opinion, and the transmission and TCM were replaced. The vehicle was repaired; however, the failure reoccurred. Upon further investigation, the contact related the failure to the Customer Satisfaction Program: N192272400; however, the VIN was not included. The manufacturer was notified of the failure, and a case was filed. The failure mileage was approximately 40,000.

NHTSA complaint #11731897 — an unverified report by a vehicle owner.

POWER TRAIN

The transmission has a shudder at various speeds.

NHTSA complaint #11729531 — an unverified report by a vehicle owner.

POWER TRAIN

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.

NHTSA complaint #11729057 — an unverified report by a vehicle owner.

POWER TRAIN

The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle vibrated and felt as if the transmission was going to unexpectedly downshift. No warning light was illuminated. In addition, there was an abnormal sound coming from the rear wheels. The contact stated that it felt like the rear tires were driving in the wrong gear. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. The contact stated that the failure persisted and became a worsening failure. The manufacturer was not notified of the failure. The failure mileage was approximately 75,000.

NHTSA complaint #11728086 — an unverified report by a vehicle owner.

POWER TRAIN

Transmission shudder and vibration at highway speed.

NHTSA complaint #11727753 — an unverified report by a vehicle owner.

POWER TRAIN

The transmission valve body was trying to lock up while driving and making it shimmy and shift hard. I took it to Davis GMC in [XXX] . They diagnosed it with the transmission malfunction (this is the same transmission that is under recall in the 2020 models)j. I paid $8660.33 to have them replace the transmission. It has been approximately 6 months and 6.000 miles and now this transmission is shuttering, also. I took it back to Davis GMC and the technician told me that I didn't know how to drive a 10 speed automatic! I then took it to TriLakes Motor in [XXX] where they made an adjustment on it. That has not fixed the problem. Today I contacted the main GMC center and started a case number: XXX. They suggessted taking it back to a dealership again and trying to get it fixed again. I feel like I am stuck with a truck that can not be fixed and should be in the recall due to it having the same transmission as the other GMC Sierra's that are under recall. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11726779 — an unverified report by a vehicle owner.

POWER TRAIN

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.

NHTSA complaint #11724048 — an unverified report by a vehicle owner.

POWER TRAIN

The oil cooler line is leaking, and the vehicle is available for inspection upon request. This safety concern is addressed under GM Program N192220080. The Hazard is Present: The leak is active. The risk of total line detachment and engine seizure is the same in Texas as it is in Alaska (the US state the GMC recalled the exact same part). An engine seizure and loss of propulsion is an immediate danger to passengers within the effected vehicle, as well as the other vehicles on the road. The Admission of Defect: GM’s offer to provide the part (Part #85136335) confirms that my vehicle’s hardware is part of the failed batch. The vehicle was inspected by an authorized GMC dealership on 01/14/2026, confirming the leak and potential safety hazard with continued driving of the vehicle. The issue was submitted to the GM Customer Care team, Case #[XXX]. The only warning of the defective oil cooler line leak was oil on the ground underneath the vehicle after driving. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11722687 — an unverified report by a vehicle owner.

POWER TRAIN

On 2/4/2026, my vehicle (2019 GMC Sierra AT4 and VIN # 3GTP9EED5KG240494) experienced a catastrophic failure of the engine oil cooler lines. This is a well-documented manufacturing defect involving the failure of the crimp joints between the rubber hose and metal tubing. This failure occurred abruptly, causing massive oil loss and posing a severe safety risk due to the potential for sudden loss of oil pressure and engine seizure while operating the vehicle at highway speeds. This specific component failure is recognized by General Motors under Customer Satisfaction Program (CSP) N212326940. GM explicitly acknowledged this failure as a manufacturing defect. Despite the fact that the defect is inherent to the part’s design—and not a result of typical "wear and tear"—GM has denied my request for reimbursement, citing that the vehicle is outside the standard 36,000-mile warranty period. I exhausted all good-faith efforts to resolve this through GMC’s internal escalation process. I spoke with a representative and a supervisor, both of whom refused to honor a reimbursement request based on the manufacturing defect. They refused to consider that the defect, as documented in GM’s own internal bulletins, is independent of mileage and that the repair was performed at an authorized GM dealership. I am seeking full reimbursement of $2,171.58 for the repair of a known, safety-related manufacturing defect. GM is failing to stand behind their "Professional Grade" standards by refusing to cover a part they have already admitted is defective. I request that your office mediate this dispute to facilitate a full refund of my out-of-pocket repair costs.

NHTSA complaint #11721265 — an unverified report by a vehicle owner.

POWER TRAIN

On Wednesday, January 7th, 2026, my wife and I were traveling North on the Northeast Extension of the Pennsylvania Turnpike (476) at approximately 9:00 pm. A check engine light came on with no other symptoms, we start to get off the next exit. While still on the highway, the motor turns off with a warning to put it in neutral and restart. It would not restart and coasted off the exit and into a convenience store parking lot. There was noise, just turned off. We got stuck in the town for over 2 days before getting a tow 209 miles to the mechanic shop. We were miles from any mechanic shop and tried to troubleshoot while waiting and to no avail. First mechanic had to send it to a second because it looked like the engine had seized and that was confirmed at the second mechanic shop. Apparently the bearings in the lower end seized. The only thing they could offer was to replace the motor. It had proper amounts of fluids and didn't overheat. The motor replacement is approximately $10,800.00 in addition to having no vehicle there was additional towing and breakdown expenses (food and lodging for 2 nights and 3 days)

NHTSA complaint #11719521 — an unverified report by a vehicle owner.

POWER TRAIN

catastrophic engine failure to due connecting rod bearings spun on the crankshaft damaging the crank and sending bearing material throughout the oil galleries

NHTSA complaint #11716202 — an unverified report by a vehicle owner.

POWER TRAIN

This vehicle shudders and vibrates during shifting and acceleration at different speeds. Transmission shifts out of gear quite often leaving me stranded at times trying to make it safely out of traffic.

NHTSA complaint #11713601 — an unverified report by a vehicle owner.

POWER TRAIN

While driving in traffic in March 2025, the vehicle experienced a sudden and complete engine failure, creating an unsafe condition. Subsequent diagnosis confirmed failure of the camshaft and lifters, requiring full engine replacement. General Motors declined to cover this repair. However, this failure is consistent with widely reported camshaft and lifter issues affecting other GMC and GM vehicles equipped with the same 6.2L engine platform. Due to the unavailability of replacement engines through GM, I was forced to wait several months for an engine sourced through Jasper Engines. During this time, the vehicle was inoperable, resulting in over $10,000 in out-of-pocket expenses, including extended rental vehicle costs. The engine replacement was completed by Camden Automotive and Diesel in Camden, South Carolina, who maintain all service and maintenance records related to this repair.

NHTSA complaint #11712140 — an unverified report by a vehicle owner.

POWER TRAIN

Catastrophic engine failure of known defective L87 engine

NHTSA complaint #11712175 — an unverified report by a vehicle owner.

POWER TRAIN

With 115000 miles on it, I felt a clunk when it went in to gear. I took it to the dealer 3 times to have the mechanic drive it. He said it sounded and felt right. The the transmission blew and I had to have it replaced to the tune of 4800 dollars. 2 weeks after that the engine blew and I had to have that replaces for 17000 dollars. I really like my pickup but this seems a bit excessive. The 5.3 engine isn't good for that year

NHTSA complaint #11710862 — an unverified report by a vehicle owner.

POWER TRAIN

I am an owner of the same year, and model GMC Sierra 1500 included in the GM Customer Satisfaction Program N212326940, which is the oil cooler line failure. However, my VIN was not included in the program despite experiencing the exact same failure the program covers. My safety and the safety of others is put at risk because the failure may cause an immediate loss of oil pressure or propulsion while driving. This is a huge safety hazard, since loss of vehicle control may occur. My vehicle has been inspected by a certified GM dealer and they confirmed the oil cooler line has failed and must be replaced. I have not experienced any warning lights, but my vehicle is leaking an excessive amount of oil. The vehicle is no longer safe to drive until repaired.

NHTSA complaint #11710942 — an unverified report by a vehicle owner.

POWER TRAIN

I live in Illinois, my 2019 GMC Sierra 1500 SLT has 51,318 miles on it as of 12/31/2025. What component or system failed or malfunctioned, and is it available for inspection upon request? Engine Oil Cooler hose line detaching from crimp - small oil leak currently. Not yet fixed. Available for inspection. How was your safety or the safety of others put at risk? If this component fails, all oil from the vehicle will be lost and inoperable. This could cause a traffic accident, especially if towing a load. Has the problem been reproduced or confirmed by a dealer or independent service center? Confirmed by an independent service center. I will be taking my vehicle to the local GMC service center for additional confirmations. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? No, but GM has acknowledged the issue through these customer satisfaction surveys (CSP XXX/ XXX). Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? There has been no failure yet. A small oil leak was found on my garage floor. My issue is that this is a known issue in cold weather climates. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11708526 — an unverified report by a vehicle owner.

POWER TRAIN:AUTOMATIC TRANSMISSION:TORQUE CONVERTER

The contact owns a 2019 GMC Sierra 1500. The contact stated that in the first month that the vehicle was purchased, the vehicle intermittently hesitated before slamming into gear hard. No warning lights were illuminated. The vehicle was taken to the dealer, and the contact was informed that the manufacturer was aware of the failure and suggested that a triple fluid flush was needed, and the triple fluid flush was performed. The contact stated that the hard shifting persisted, especially while driving uphill. The vehicle was taken back to the dealer, where it was diagnosed and determined that the torque converter had failed and needed to be replaced. The vehicle was not repaired. The failure persisted, and the vehicle remained at the contact's parents' residence unrepaired. The manufacturer was not notified of the failure. The failure mileage was approximately 57,000.

NHTSA complaint #11706562 — an unverified report by a vehicle owner.