GMC Sierra Complaints

15,732 consumer complaints on file.

#11729323April 5, 2026
ENGINE
Motor locked up on highway with heavy traffic trying to exit highway
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11729002April 3, 2026
SERVICE BRAKES, HYDRAULIC
The contact's partner owns a 2019 GMC Sierra 1500. The contact stated that upon starting the vehicle, the "Service Brake System" and ABS warning lights illuminated. The brake pedal was depressed to the floorboard, and the message that the vehicle would not exceed 62 MPH was displayed. The vehicle was restarted, and several unknown warning lights were illuminated with a message that the vehicle would not accelerate above 42 MPH. The vehicle was taken to a dealer, where a diagnostic test was performed and the diagnostic test revealed that the brake pipe had seized in the brake master cylinder and that the pipe fitting threads were damaged. The contact was informed that the brake master cylinder and the reservoir seal needed to be replaced. Despite the repair, the dealer stated that the master cylinder and brake line fitting were still defective. After several additional repairs to the brake system, the vehicle was returned to the owner. Upon driving the vehicle, the contact stated that the prior brake warning lights returned on the instrument panel. The vehicle was returned to the dealer and remained with the dealer. Upon investigation, the contact discovered NHTSA Campaign Number: 20V055000 (Service Brakes, Hydraulic); and associated the failure with the recall. The manufacturer was notified of the failure, and the contact was informed that the vehicle was not included in the recall. The contact was then given a case number. The contact was also transferred to the NHTSA Hotline to report the failure. The vehicle was not repaired. The failure mileage was 42,320.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11729013April 3, 2026
ELECTRICAL SYSTEM, ENGINE, POWER TRAIN
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11729038April 3, 2026
FUEL/PROPULSION SYSTEM
The service department has identified "gasoline contamination" as the cause of a fuel system failure; however, this diagnosis is directly contradicted by both the shop’s internal test results and independent laboratory analysis.the shop performed an API Gravity test and a Styrofoam cup test.•API Gravity Result (35): According to GM Service Information (GMSi), the standard API range for #2 diesel is 30–39. result of 35 is a textbook "pass" for clean diesel. Gasoline contamination would typically spike this number into the 50s.GMSi protocol indicates that gasoline-contaminated diesel will melt a cup within 30 minutes.results only provided a "softened bottom," which is an inconclusive result per GMSi standards.Sinclair Refinery lab confirms the fuel sample taken from my vehicle is within 100% of factory specifications for diesel, with zero gasoline or DEF detected.Violation of GM Service Protocols even assuming the shop’s diagnosis of contamination was correct, the repair performed deviates dangerously from GMSi requirementsFor a 2024 L5P Duramax that has been cranked with contaminated fuel, GMSi (e.g., Bulletin 16-NA-376) mandates the replacement of the entire high-pressure fuel system, including the pump, both fuel rails, and all eight fuel injectors. shop replaced only the pump and cleaned the lines. This "partial repair" is not a GM-approved recovery procedure for contamination. Reusing potentially contaminated injectors and rails is the primary cause of catastrophic repeat failures.This clearly falls under warranty work and I should not had been charged for this repair. The dealership refusing to acknowledge my concerns and evidence is not only dangerous to the safety of myself and passengers, but raises concern for my vehicles future maintenance status, both inside and out of warranty. This shows a deceptive business practice and complete lack of accountability, compassion and moral understanding for the customer.I am owed a full refund and a warranty claim open
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11729049April 3, 2026
ENGINE, FUEL/PROPULSION SYSTEM
Began with a misfire on cylinder 5 code P0305. Replaced spark plugs, wires, and coil pack. Misfire still existed. Fuel injector on cylinder 5 was stuck open and had to be replaced. Misfire still existed. No spark from new coil pack on cylinder 5, replaced coil pack connector. Misfire still existed, but lifter tick became present. Removed cylinder head and found exhaust lifter on cylinder 5 was bad and needed replaced. Currently awaiting parts delivery (only available through GM dealer). Have been without vehicle for 7 weeks now. Was told this was most likely related to Active Fuel Management.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11729057April 3, 2026
ENGINE AND ENGINE COOLING, 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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11729098April 3, 2026
POWER TRAIN
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728804April 2, 2026
ENGINE
When the truck was idling the dod/afm turned on and disabled a cylinder and now I’m just having codes pop up for cylinder misfires
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728807April 2, 2026
POWER TRAIN
The contact owns a 2018 GMC Sierra Denali 1500. The contact stated that on several occasions while driving at speeds over 30 MPH, the vehicle started shaking abnormally. The contact stated that the vehicle stalled while driving on three separate occasions and stalled twice while slowing down. There was no warning light illuminated. The vehicle was able to restart each time, but on one occasion, several attempts were needed to restart the vehicle. The vehicle was taken to a dealer, where it was diagnosed, and determined that the transmission, torque converter, exhaust gaskets, filter, and 8D fluid needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 87,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728906April 2, 2026
POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:VALVES/VALVE BODY
The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving on several occasions at speeds above 30 MPH, the vehicle shuddered abnormally. There was no warning light illuminated during the failures. The vehicle was taken to a dealer, where it was diagnosed, and determined that the valve body needed to be replaced. The vehicle was repaired, but the failure recurred approximately six months later. The manufacturer was notified of the failure. The failure mileage was 81,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728911April 2, 2026
ENGINE AND ENGINE COOLING
The contact owns a 2022 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the engine seized. The vehicle coasted over to the shoulder of the road. No warning lights were illuminated. The vehicle was towed to the dealer, where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The contact stated that the vehicle was repaired under NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling) in February 2026. The contact stated that a PicoScope test was performed. The contact was informed that the vehicle passed the inspection. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 41,200.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728940April 2, 2026
ENGINE
My vehicle is at the dealership now - it wasn’t starting properly, started always getting low on oil which I took to the dealership for them to monitor- and then the check engine light came on- once that came on just last Thursday I did not drive the vehicle except to the dealership to be inspected - which my appt was Monday and they found metal shavings in the oil and said the whole engine needs replacement!
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728421April 1, 2026
ENGINE
THE ENGINE COMPLETELY SHUTS OFF WHEN I STOP AT A STOP SIGN OR STOP LIGHT. I HAVE BEEN STUCK IN TRAFFIC INTERSECTIONS ON SEVERAL OCCASIONS UNABLE TO MOVE WHEN THE LIGHT TURNS GREEN. EVENTUALLY THIS WILL LEAD TO ME GETTING REAR ENDED AND PUSHED INTO IN THE MIDDLE OF AN INTERSECTION. MY LIFE IS IN DANGER WHEN I DRIVE THIS VEHICLE. I GOT MY ENGINE REPLACED AND STILL THE SAME ISSUE IS OCCURRING WITH THE AUTO STOP AND START SYSTEM.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728443April 1, 2026
ELECTRICAL SYSTEM, ENGINE
The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving at various speeds, the vehicle lost automotive power; however, the vehicle maintained electrical power. The check engine warning light was illuminated. The vehicle was towed to a local service center, where it was diagnosed and determined that the battery needed to be replaced. The vehicle was repaired; however, the failure reoccurred. The vehicle was taken back to the same local dealer and remained for additional investigation. The contact attempted to restart the vehicle several times and shift into different gears; however, the failure reoccurred. The local dealer was contacted, but the vehicle was not diagnosed or repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 103,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728444April 1, 2026
ENGINE
There is a recall on the 6.2 motor that is in my truck at my last oil change they performed a pico scoop diagnostic on the truck said it passed and gave it the new type of oil and oil cap that was suppose to fix it. Now a couple months later I walk out start my truck to let it warm up and after starting all of a sudden the engine started nocking bad and loss of oil pressure and on dip stick. I looked it up and this is what happens when the engine fails due to the massive recall on the 6.2 engines. I called the dealer and they are having me tow the truck potentially at my expense for them to look at and decide if it falls into the category of the recall after they did the test, and at one point told me that cause they did the test it is no longer recalled. I am being told people who have had the engines replaced because of the recall that the replacement engines have failed as well. I have a 9 month old baby and this left me stranded and unable to pick him up from daycare I had to scramble to find somone able to do so. I'm concerned that this could have happened while driving and having him with me or being left stranded somewhere.I'm glad it didn't happen when I was dropping him off that morning and while I was driving And meanwhile while they look at the issue and decide weather this falls under there recall or not and while it gets repaired I'm left without a vehicle and to be honest I don't feel safe even if they do repair it as there seems to not be an actual fix to the situation. this is unsafe and unacceptable for the price we have to pay for these rigs and the safety regulations and standards we have, how is this even an issue.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728447April 1, 2026
ENGINE
-The engine in my 2021 GMC Denali 1500 with the 6.2L engine failed its second engine with ~4,000 miles on the new engine. It is currently at GMC dealer waiting for a 3rd new engine. - Fortunately i was parked when the failure happened and the engine locked up. -Dealer confirmed that a valve dropped and damaged the cylinder wall. - There were no warning lamps or other indication that a failure was about to happen. -Current mileage ~91,000. First motor changed ~85,000 due to recall with previous owner.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728457April 1, 2026
ENGINE
The contact owns a 2021 GMC Sierra 2500. The contact stated that while driving at 55 MPH, the vehicle stalled unexpectedly. There were no warning lights illuminated. The vehicle was taken to the local dealer, where it was diagnosed, and determined that the engine needed to be replaced. The engine was replaced; however, the failure recurred. While at a stop and attempting to drive around a curve, the vehicle stalled. No warning lights were illuminated. The vehicle was taken to the local dealer, where it was diagnosed with engine failure. The vehicle was not repaired. The failure mileage was approximately 77,000. The VIN was not available.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728466April 1, 2026
FUEL/PROPULSION SYSTEM
On 18 March 2026 I was driving at night at highway speed with my family (wife, [XXX] son, [XXX] daughter, and [XXX] son) when, without any warning, my 2023 GMC Sierra AT4 with 20,700 miles abruptly and violently shuddered and reduced speed from approximately 65 mph to 30 mph uncontrollably. Shortly after the initial speed reduction the vehicle presented simultaneous alerts that it was in "reduced acceleration mode", the "emission system control" had failed, and the that the check engine light was on. Although the vehicle claimed to be in reduced acceleration mode I was unable to prevent it from continuously slowing to 0 mph. I attempted to use the accelerator to move from the left lane of traffic to the right shoulder without causing an accident. However, the vehicle violently shuddered and would not accelerate or maintain speed. I managed to maneuver around traffic and stop the vehicle on the right shoulder. Due to the unlit highway and my family's emotional state after the incident, I determined the safest course of action was to attempt to get the vehicle to a nearby parking lot. After turning the vehicle off and back on, I managed to slowly drive with my flashers on (despite the vehicle continuing to violently shudder) approximately 1 mile to a Wal-Mart parking lot. Once there I noticed I received an email from OnStar Diagnostics that my vehicle experienced a significant engine malfunction with an associated P129F code. I coordinated for the vehicle to be towed to Bill Cramer Chevrolet GMC Inc in [XXX] the following day. My vehicle had no lights, messages, or symptoms of this issue prior to it occurring. The dealership replaced the fuel pump power control module under warranty, cleared the faults, test drove the vehicle, and returned to me on 31 March 2026. The dealer mentioned they service roughly two vehicles of similar make and/or models daily for the same issue. 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
#11728507April 1, 2026
POWER TRAIN, ENGINE AND ENGINE COOLING, ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:UREA INJECTION SYSTEM (DEF)
The contact owns a 2025 GMC Sierra 3500. The contact stated that the transmission was shifting hard and was jerking while shifting gear. Additionally, the vehicle failed to accelerate above 50 MPH. The messages “Reduced Acceleration” and “DEF Low” were displayed. While refueling the vehicle, the fuel gauge failed to correctly display the level of fuel inside the fuel tank until the vehicle had been driven for approximately 20 minutes. The vehicle was taken to the dealer to be diagnosed, and the contact was informed that the transmission needed to be updated. The system was recalibrated; however, the failure persisted. The vehicle was taken to another dealer, George Kell Motors (3808 Van Dyke Rd, Newport, AR 72112); and the system was recalibrated. However, the failures persisted. While driving approximately 60 MPH, the transmission was shifting hard, and the vehicle took over 2 hours to drive 19-miles. The engine temperature gauge fluctuated between 185 and 188 degrees. The vehicle was pulled over to the side of the road to cool down before continuing to drive, while not exceeding 40 MPH. The vehicle was taken to a third dealer, Fremont Chevrolet GMC Riverton (1401 N Federal Blvd, Riverton, WY 82501); who determined that the bell body needed to be replaced. The vehicle was scheduled to be repaired, but parts were on back order. The contact became aware that there was a recall related to failure; NHTSA Campaign Number: 26V129000 (Fuel System, Gasoline); however, the VIN was not included. The manufacturer was not made aware of the failure. The failure mileage was approximately 40,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11728176March 31, 2026
STRUCTURE:BODY
While driving under normal conditions, a front grille trim component detached from my vehicle without any impact or external cause. The piece became airborne and struck my windshield, creating an immediate safety hazard and risk of loss of control. There was no prior damage or warning. This represents a failure of a vehicle component under normal operation and indicates a defect in materials, design, or installation. Exterior parts should not detach and become projectiles at roadway speeds. The manufacturer has been notified but has declined responsibility. Given the safety risk, this may not be an isolated issue.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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