GMC Sierra Complaints

15,732 consumer complaints on file.

#11762401September 6, 2026
POWER TRAIN, ENGINE
I own a 2018 GMC Sierra 1500 V8 5.3 liter which is at 46, 433 miles. Over the past few weeks I have noticed the transmission having difficulty shifting in first gear and lurching, and making shuddering noises, and as well making a constant ticking noise. After an experienced mechanic had put a diagnostic system onto my truck, his system diagnosed a Transmission Lifter Failure, specifically 2 out of the 8 lifters. A few days later (9-04-26) I took my truck to a certified GMC servicing business (Patriot Chevrolet of Hopkinsville KY 270-886-1207) and had a transmission servicing done. I had told the Customer Service representative Amanda Williams about the ticking and that I thought 2 lifters going bad in the transmission were the source of it. 3 hours later the servicing was done which cost $ 474.43. She did not know if the ticking had stopped or not. I started my engine to head home and the ticking was still happening. Nothing had changed. I got home, parked and have not started the engine since to minimize any further damage. I have become aware that this year, make and model has become infamous for the engine/transmission design and parts failure which has been at the center of thousands of class action lawsuits. I have owned this vehicle since inheriting it from my late father for 2 months before he developed dementia and suffered a broken hip. I have religiously had the oil changed every three months regardless of the mileage, and this is a sealed transmission which cannot be worked on by someone but a certified GMC mechanic, which wasn't a worry because the truck's manual says doesn't need to be worked on unless there seem to be problems. Which is what I did on 9-4-26, hoping that a servicing would fix the issue. During the 5 years that I have owned this truck, I never received ANY sort of notice from GMC that might've hinted at possible Transmission Failures, though GMC has been totally aware of. Sudden power loss dangerous and unfairly expensive to drivers.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11762323September 5, 2026
ELECTRICAL SYSTEM
When I try to start my truck it comes up as service trailer brake control module and it has caused my truck battery to drain so I cant even crank my truck up.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11762400September 5, 2026
ENGINE
I was notified my lifters in my 6.2 L V8 would need to be inspected for any defects. When I purchased my vehicle from Car Max here in Jackson, MS, I received a notification from the dashboard that the engine oil was low and to add oil. I turned around and took it back to the dealership as soon as possible. This happened on the first day of owner ship with in 5 minutes of driving off from the lot. I Car Max told me to just add oil and bring them the receipt and they would reimburse me. I chose not to and asked them to service the vehicle to avoid any issues with my warranty or my Car Max Shield Warranty. 2,000 miles later the same notification came across the dashboard again. I took it back to Car Max immediately and they ended up sending it off to my local GM dealership for service. They topped it off with oil after inspecting it for any leaks in the engine. None were discovered. After the 3rd notification about the engine oil level being low after close to 3,000 miles, they serviced the vehicle and put the vehicle under the Oil Consumption Watch. This took place from October 2025 through September 2026. After multiple visits, they informed me they would need to perform further test to see if the lifters were failing and that I would be responsible for the labor fees estimated at around $632.82. I informed them I have Car Max’s 150,000 mile warranty. Fidelity Insurance company informed me they would need to send an inspector out to the GM dealership. Before this takes place, they would need the vehicle to undergo various tests and I would be responsible for the labor fees. Should the engine components be found worn down. Fidelity would not cover the repairs. Should the engine components be found defective, they would cover the replacement part but not the label. Labor costs would estimate around $2,978.95. I asked the GM dealership to share this information with me in writing for documentation purposes. I asked for my vehicle to be parked until further notice.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11762072September 4, 2026
POWER TRAIN
The contact owned a 2026 GMC Sierra 1500. The contact stated that while slowly driving up a slightly inclined driveway and making a left turn, the engine shut off. The contact stated that either the parking brake activated, or the vehicle suddenly decelerated. The contact stated that the failure had occurred several times, with three identical vehicles, including the loaner vehicle provided by the dealer. During the failure, the messages, "Press Start" and "Service Transmission" were displayed. The vehicle was taken to the local dealer who was unable to determine the cause of the failure. The vehicle was not repaired. The vehicle was later traded in for an identical vehicle. The manufacturer was notified of the failure.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11762122September 4, 2026
POWER TRAIN
Within the first 3 years of purchase as a new vehicle, my 2018 GMC Sierra Denali equipped with the GM 8L90 automatic transmission developed a pronounced judder during light acceleration, resembling driving over rumble strips. The condition was first reported to an authorized GMC dealer on October 23, 2021, at 26,648 miles while the powertrain warranty was in effect. GM authorized a transmission-fluid exchange from the technical service bulletin (TSB) 18-NA-355, dated April 2020, but that repair did not provide a lasting correction. The condition continued, and in 2026 the authorized dealer diagnosed an “internal stator issue causing judder on light acceleration” and recommended replacement of the torque converter. We completed the repair and retained the removed converter. The defect affected the vehicle while accelerating and created concern about predictable power delivery when merging, entering traffic or crossing an intersection. Continued torque-converter malfunction can generate heat and debris, damage the transmission and potentially impair acceleration or power transfer. GM had issued technical bulletins addressing torque-converter shudder in 2018 Sierra vehicles before this truck was purchased, but there has been no recall. I request that NHTSA evaluate whether this recurring defect presents an unreasonable safety risk in GM vehicles equipped with the 8L90 transmission.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761815September 3, 2026
VEHICLE SPEED CONTROL, POWER TRAIN
While driving my truck on the highway at 65 mph the truck bucked hard and immediately downshifted into 2nd gear. This caused me to rapidly decelerate to approximately 40 mph, I am lucky there was not another vehicle behind me when this happened since rapid unexpected deceleration without brake lights is very dangerous. I had to drive the truck in limp mode at 45mph and approximately 4500 rpms to the nearest exit. This event illuminated the trucks check engine light and displayed a brief service 4WD message followed by a permanent reduced acceleration message on the dash.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761833September 3, 2026
STRUCTURE:BODY
My 2022 GMC Sierra 1500 was subject to GM safety recall N242490120 / NHTSA 25V060 for an upper grille deflector that could detach from the vehicle. The recall repair was completed by my GM dealership in June 2025. In late August 2026, while driving normally on the highway, the same upper grille deflector detached again in the exact manner described by the recall. There was no collision, impact, or other outside damage that caused the failure. I was able to retain the detached deflector due to my attentiveness however, it was close to detaching and either busting mine or someone else’s windshield. Upon inspection, the adhesive and retainers from the previous recall repair are still clearly visible, and the bonding appears to have separated. I have photographs documenting the failed attachment points and still possess the undamaged detached component for inspection. My GM dealership inspected the vehicle after this failure and determined that the front grille assembly should be replaced. However, because the recall is shown as previously completed, GM has stated that the recall cannot be reopened. GM Customer Assistance offered only $251 toward a $1,673.82 repair, leaving me responsible for $1,422.82 to correct the same safety defect that the recall was intended to remedy. I am filing this complaint because the recall remedy appears to have failed, allowing the recalled component to detach from the vehicle again. A grille component detaching at highway speed could strike another vehicle or create a roadway hazard. I am concerned that other vehicles repaired under this recall may experience the same post-recall failure. I request that NHTSA review the effectiveness and durability of the remedy used for recall N242490120 / 25V060.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761844September 3, 2026
POWER TRAIN
The contact owns a 2026 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the transmission independently shifted to park or neutral. The contact stated that the failure had occurred while driving at slow speeds. The contact stated that during one failure, the brakes independently activated, and the vehicle shut off. The contact stated that while attempting to restart the vehicle, the vehicle started. The contact stated that the failure was persistent. The dealer was made aware of the failure by phone. The vehicle was taken to the dealer; however, the diagnostic result was not provided. The failure mileage was approximately 500.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761850September 3, 2026
ENGINE
Lifter locked up causing bent push rod. This situation caused truck to strand the driver without warning. Truck needed to be towed. This repair was performed by the dealership and is a known issue with 6.2 L engine.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761880September 3, 2026
ENGINE
The vehicle was part of the GM L87 engine recall. The vehicle was taken to the dealership in late 2025 for recall service. The dealership inspected the vehicle for vibration and determined that it required an oil change and updated service manual to require 0W-40 oil. On June 21, 2026 the vehicle experienced an engine failure.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761903September 3, 2026
STRUCTURE
The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving 70 MPH and looking in the driver’s side mirror, the contact became aware that an unknown object had detached from the vehicle. The contact was unaware that the chrome front grille deflector had detached until arriving at the residence. The dealer was contacted, and the vehicle was taken to the dealer to be diagnosed, and the contact was informed that the chrome front grille deflector needed to be replaced. The vehicle was not repaired. The contact associated the failure with NHTSA Campaign Number: 25V060000 (STRUCTURE); however, the VIN was not included in the recall. The failure mileage was 48,210.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761966September 3, 2026
POWER TRAIN
The contact owns a 2026 GMC Sierra 1500. The contact stated that while slowly driving up a slightly inclined drive port and making a left turn, the vehicle shut off and the parking brake was activated or the vehicle suddenly decelerated. The contact stated that the failure had occurred on several occasions with three separate identical vehicles, including the loaner vehicle provided by the dealer. During the failure, the messages "Press Start" and "Service Transmission" were displayed. The vehicle was taken to the local dealer who was unable to determine the cause of the failure. The manufacturer was notified of the failure. The failure mileage was 29.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11762000September 3, 2026
ENGINE
So I spent many months trying to aquire a GMC Sierra Denali and with all the issues with the 20 - 24 6.2 engines we were assured by the dealer that all the issues were resolved with the 2025 6.2 models. So we spent big to aquire an 2025. So I bought one new. My truck had 8000 miles on it with 2 oil changes. So we booked a trip to [XXX] at considerably a large expense and loaded up our Harley's on my light aluminum trailer, less than 3.5k pounds and headed that way from [XXX]. We made it to [XXX] and spent the night. Next morning we were heading to [XXX] and the truck blew up on the XXX. We were pulled over on a very busy hi way and had to get truck and trailer towed back to [XXX]. We were stuck there for 3 days while GMC installed a rebuilt motor in my 83k truck and totally missed our entire vacation. On line it said GMC would cover hotel and 40.00 dollars a day food. I am so disgusted after being reassured that GMC had fixed the 6.2 and putting our life in danger blowing up on a major highway, and afterward GMC only gave us 200. For our inconvenience. Our room alone was more not counting the money lost on out trip accommodations. I am so completely disappointed with this truck that we bought new and spent more than we ever had on a vehicle, and am afraid of ever taking another trip in it. How can GM be allowed to do this to people. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11762005September 3, 2026
ENGINE
I purchased a 2024 GMC Sierra 1500 Denali Ultimate equipped with the 6.2L V8 engine on XXX. The vehicle currently has approximately 25,000 miles. On XXX, the vehicle underwent the GM recall repair related to the 6.2L engine at Don Mealey Chevrolet. On XXX, approximately nine months after the recall repair, my family and I were traveling on the [XXX] with my two children inside the vehicle when the engine suddenly experienced a major failure. The vehicle became inoperable while we were traveling on the highway and had to be stopped and subsequently transported to Schumacher Buick GMC in [XXX]. The failure occurred unexpectedly while the vehicle was being operated normally. Having an engine failure while traveling on a major highway with my two children in the vehicle created a significant safety concern because of the potential for loss of power and the danger associated with becoming disabled in active highway traffic. GM has subsequently authorized replacement of the engine under warranty. The vehicle remains at the dealership awaiting completion of the engine replacement. I am reporting this failure because the vehicle had previously received the GM recall remedy for the 6.2L engine issue and subsequently experienced a major engine failure at only approximately 25,000 miles. The failure occurred approximately nine months after the recall repair. I am concerned that the previous recall remedy may not have adequately addressed the underlying condition associated with these 6.2L L87 engines. I am requesting that NHTSA document this failure as part of its investigation into 6.2L L87 engine failures and evaluate whether the existing recall remedy adequately addresses the safety-related engine failure condition. Vehicle information: * [XXX] GMC [XXX] 1500 Denali Ultimate * 6.2L V8 engine INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11762016September 3, 2026
ENGINE
2020 GMC Sierra 1500 AT4, 3.0L LM2 Duramax. In service 08/13/2020. Five glow plug failures on five different cylinders in under 19,000 miles, all at one GM dealer, all part 24000504: Cyl 1, 10/21/2024, 38,650 mi, P0671, RO 13714, warranty. Cyl 6, 11/05/2024, 38,793 mi, P1330, RO 26665, warranty. Cyl 4, 11/29/2024, 39,683 mi, P133B, RO 57498, warranty. Cyl 3, 01/22/2026, 52,959 mi, P0673/P06C7/P133A, RO 100951, I paid $713.38. Cyl 2, 08/26/2026, 57,466 mi, P06C6/P0672/P1339, RO 115953, GM under N232430460. The first three came within 39 days and 1,033 miles. Every RO documents the same finding: high internal resistance in the plug, circuit tests good. The failure is internal to the plug. Glow plug failure on a diesel causes hard starting, extended cranking, no-start in cold weather, and startup misfire - risk of being stranded or unable to start. GM has documented this defect three times: PIP5762 (12/2020), TSB 22-NA-027 (2/2022), Special Coverage N232430460 (1/2024). All name an inadequate camshaft housing cover baffle plate weld, and all limit the remedy to cylinder 2. On the recorded walkaround for RO 115953 the tech stated my engine serial falls inside the affected population and my earlier failures were probably the same condition. GM replaced only the glow plug. The camshaft cover GM identifies as the cause is still installed; GM quoted me $5,100 to replace it at my expense. Four of five failures were on cylinders 1, 3, 4 and 6, outside that scope. If the bad weld passes oil into the PCV and intake path rather than only the cylinder 2 glow plug well, ingested oil would reach other cylinders. No RO shows anyone inspected the intake tract, charge piping, cooler, PCV separator, a removed plug, or a glow plug well. I ask ODI to examine whether the cylinder-2-only scope of N232430460 is under-inclusive, whether replacing the plug while leaving the cause installed is an adequate remedy, and whether repeated internal failure of part 24000504 warrants a recall.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761482September 2, 2026
ENGINE
I was coming to a stop at a stop a 3 way stop intersection. I parked completely and when I stopped the vehicle just shut down I did not have any warning signs come on prior as I looked at the dash it said place vehicle into park and start. I tried that but truck did not start. Call my friends we towed the truck on a trailer to my house and set up an appointment with gmc here in Tucson az
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761504September 2, 2026
ENGINE
My vehicle is under the L87 Recall from GM for engine failure. In September 2025 it was given the recall “fix”, different thicker oil. But on July 1 2026, my engine seized while I was driving 60 mph on the highway. GM has since replaced the entire engine and the radiator. But the “fix” obviously did not work.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761506September 2, 2026
ENGINE
I received a notice months ago for possible engine problems. my dealer checked it out and everything was good except for changing oil from 0W-20 to 0W-40. i was in Atlanta, GA on 8/26 and by the time i got home on 8/27, engine was knocking. I barely made it home. the dealer has had the truck since. they said i have to have a new engine. no idea when they will get one inn or when i will get my truck back. i opened a claim with GM (Case #108927907). GM basically offered no assistance, help, etc. i even tried to trade the truck back to my local GM dealership for another truck and they wouldn't offer enough on trade inn (says they wouldn't be able to sell it), GM Corporate wouldn't offer buy back, loyalty program money, etc. as they claim it's under a recall. I have never received anything about a recall for the engine. local Ford or Toyota dealerships will not even consider taking it in on a trade after new engine, says they cannot sell because of engine issue with 6.2L engine. so i'm stuck with a truck that i cannot sell or trade and is now worthless. I'm sure the new engine will fail as well.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761542September 2, 2026
ENGINE
Engine stopped working while driving 65 mph on I435 Kansas City. Engine failure had to pull over in 3 lane traffic to get off of roadway. Engine just stopped working. Had towed to GM dealer who performed full engine replacement. 6.2 L . No warning. Just stopped working. Safety traveling on 3 land highway engine stopped with no warning had to work way over the shoulder with no engine.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761573September 2, 2026
ENGINE
After the initial recall inspection was performed, I was informed that my vehicle was not affected. Subsequently, the vehicle experienced a catastrophic engine failure while traveling westbound on [XXX] near [XXX], approximately one mile from [XXX]. While traveling at highway speed, the vehicle suddenly began losing speed and power. I was positioned between two semi-trucks, creating an extremely dangerous situation. At first, I looked to see if I was traveling uphill because of the unexpected loss of speed. I then pressed the accelerator in an attempt to maintain highway speed. The vehicle abruptly downshifted and the engine RPM increased dramatically. Immediately afterward, warnings appeared on the instrument cluster, including “Engine Oil Temperature High” and instructions to pull over and allow the vehicle to cool down. The vehicle continued to lose power, creating a serious risk of collision due to the surrounding highway traffic. The vehicle was subsequently towed to Findlay GMC, where it was inspected and diagnosed with a failed engine. The engine was ultimately replaced. This failure occurred after the vehicle had been inspected under the recall and I had been advised that it was not affected. I am concerned that my vehicle may have been incorrectly excluded from the recall or that the recall does not adequately identify all affected vehicles. The sudden loss of propulsion at highway speed presented a significant safety risk and warrants further investigation. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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