GMC Sierra Complaints
15,732 consumer complaints on file.
- #11748595July 6, 2026ENGINE
The cam shaft bearing failed under normal driving conditions. Many of the service engine lights including brakes and primary service engine light came on after the cam shaft bearing failure. The engine was replaced by a GM dealership at 65,000 miles and was inspected to determine the cam shaft bearing failed. Luckily the engine failed at a speed of 35 mph on an off ramp, as a complete engine failure on the highway could have been much more dangerous. Following the replacement of the engine, within 500 engine miles, O2 sensors in the catalytic converter were replaced and ultimately the catalytic converter had to be replaced as well.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11748623July 6, 2026ENGINE
Since purchase of my 1500 Sierra 6.2L on 10FEB2021, the vehicle has always appeared to burn an excessive amount of oil which is consistent with GM’s 6.2L engines and has created safety issues leading to sweeping recalls on this engine model from 2021-2024. I have been informed that the engine was consistently down 2+ qts of oil at every recommended oil change (approximately every 5000mi) although GM literature indicated that this level of consumption was usual in their 6.2L engine. In a JAN26 oil change at approximately 35,000mi I was told that my engine was down over 3qts of oil. On 17FEB2026 I took my vehicle into my Chevy/GMC Dealership to request an oil consumption test at ~35, 089mi. On 30JUN2026 I returned to the dealership for my 2000mi check-in, at ~37,800mi, and was informed that my vehicle had failed the consumption test. With over 600,000 vehicles recalled since 2024 in the 6.2L category, my vehicle/VIN has never been associated with a recall. Despite having minimal miles on this engine, I am now financially penalized for repairs because I had just exceeded the initial Powertrain Warranty and my extended warranty would not cover a pre-existing condition. GM’s 6.2L engines have pre-existing issues from the factory and represents a danger to consumers and the driving public because of these failures.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11748647July 6, 2026FUEL/PROPULSION SYSTEM, POWER TRAIN
Dashboard lit up with engine light and stated that there's no compulsion
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11748270July 4, 2026ENGINE
My gmc sierra had no warning lights, on the way to work on the highway it started making noises which increase every mile .Vehicle just turned 60.049miles . Engine completely seized up , low oil pressure light on , vehicle shuts off , luckily making to the shoulder and off the road. Gm towing wasn't any help in middle of the winter with 0° outside that morning , they told me that it's not covered under warranty and it would take 3 hrs for towing to get to me and out of my packet cost . Dealer diagnosed issue , found code P0016 (crankshaft position-intake camshaft position not plausible) also found excessive amounts of metal in the oil. Vehicle was repaired and second engine was installed .
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747926July 2, 2026ELECTRICAL SYSTEM, STEERING, UNKNOWN OR OTHER
Truck shut off and would not turn back on. Negative battery cable so hot it burned skin off. Would not start, tried to start clicking sound, radio blipped for a moment.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747986July 2, 2026UNKNOWN OR OTHER, ELECTRICAL SYSTEM
My HMI was "bricked" when onstar pushed an incompatible update when I changed the service plan. While driving the screen has intermittently turned off and on causing temporary unexpected loss of navigation functions, Bluetooth connectivity, and use of the back up camera. This causes a safety issue as the unexpected loss of display and connectivity has caused me to be unable to continue using hands free features during operation, and to no longer view behind the vehicle during entirety of backing. When I contacted OnStar support I was instructed to perform some troubleshooting and was then referred to the Connection Center Team. The CCT representative told me that my hardware was outdated and could not support the update. If a representative can confirm the problem retrospectivly, I think the representatives making changes to the service plan should also be able to proactively confirm incompatibility before causing the issue. There were no warnings. The issues first occured while I was driving on the day (6/25/26) my new plan began and the update was sent. I can make the HMI available for inspection upon request. I don't believe there is any actual issue with the hardware, just a negligent and incompatible software update.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11748009July 2, 2026ENGINE
While driving vehicle on state highway exit at approximately 55 mph a knocking noise started coming from engine then engine just died and would not restart. Engine was replaced under recall.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11748047July 2, 2026ENGINE
Sudden catastrophic engine failure with only 6000 miles on vehicle on May 26, 2026. 2026 GMC Sierra 1500 AT4X with known defective 6.2L L87 V8. Had to coast across three lanes of traffic to get to other median as highway location was on large curve. Someone very easily could have been hurt or killed.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11748050July 2, 2026POWER TRAIN, ENGINE, FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
The vehicle suffers from a persistent transmission defect including shuttering bucking slipping torque converter failure valve body failure twice metal debris improper down shifting chirping noises and related liability and safety issues. The vehicle has undergone multiple unsuccessful repair attempts at authorise GM dealerships. These repairs include torque converter replacement valve body replacement twice solenoid replacement fluid services software updates. The transmission problems have persisted despite these efforts and the vehicle has been out of service for more than 22 business days including a breakdown driving to Florida. I have filed a claim through GM but it seems like it just keeps getting pushed further and further away this is a serious safety issue as I fear for those driving around me and myself that I may cause an accident with the bucking slipping and failure to operate properly on the road.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747670July 1, 2026SERVICE BRAKES
Failure to release parking brake. Lining material improperly bonding to steel shoe from Manufacturer. Service Parking Brake warning Indicator “on”
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747619July 1, 2026STRUCTURE:BODY
The front grille/hood trim flew off driving down the highway. No, it is not available the cheap plastic shattered. My safety was put at risk b/c parts are flying off the truck that should never. More importantly other people's safety is put at risk b/c a long SHARP plastic piece is flying off a large truck driving down the highway!! Yes, Glenn Polk has seen the damage and can confirm. No, no one else has inspected it yet but you gladly can, it doesn't take a genius to see that the cheap POS plastic was terrible engineering by GM. There were no warnings or indications that the piece was even loose.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747646July 1, 2026ENGINE
This vehicle became subject to a manufacturer safety recall requiring complete engine replacement. The engine failure has been confirmed by an authorized GMC dealer, and the vehicle has remained out of service for more than one month while awaiting the recall remedy. The dealer has advised that the repair has been escalated through GM's SPAC (Service Parts Assistance Center) process because a replacement engine is not available. General Motors has also confirmed there is currently no estimated delivery date or estimated completion date for the repair. As a result, the recall remedy is effectively unavailable, and the vehicle remains unusable for an indefinite period. Although a temporary loaner vehicle has been provided, it is not functionally comparable to the recalled vehicle and does not provide the towing capability and utility required for its intended use. The vehicle was inspected by an authorized GMC dealer, who confirmed that engine replacement under the recall is required. The vehicle remains available for inspection. My concern is not only the original safety defect but also the inability to obtain the recall remedy within a reasonable timeframe. There has been no estimate of when replacement engines will become available, leaving the vehicle out of service indefinitely. I am submitting this complaint to document the delay in completing the safety recall and to request that NHTSA review whether the recall remedy is being provided in a timely and effective manner.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747347June 30, 2026ENGINE AND ENGINE COOLING
The contact owns a 2020 GMC Sierra 2500. The contact stated that the check engine warning light was illuminated, and the message "Reduced Power" was displayed. The vehicle was taken to the dealer, where the turbo actuator and wastegate position sensor A-circuit were replaced; however, the failure persisted. The vehicle was taken back to the dealer, and the contact was advised that another diagnostic test was needed. The contact declined to pay for the diagnostic test. The vehicle was taken to a retired GM mechanic, who diagnosed the vehicle with turbo charger failure. The vehicle was not repaired due to the cost. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was approximately 100,000.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747468June 30, 2026ENGINE
The engine had a critical failure at 49,000 miles. It was replaced under the drivetrain warranty. That came with a 12 Month, 12,000 mile warranty. Now I have a SECOND engine failure at 59,000 Miles. This will come with only a 12 month 12,000 mile warranty because it is NOT under recall. ALSO my transmission is now slipping and they are replacing the Valve Body. They had my truck for 4 months the first time and one month this time. These are the exact same issues with 2021 - 2025 GMC 6.2L and 10 Speed Transmissions. If I the issue had happened 6 months later I would have NO warranty. I want a recall on 2020's please.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747508June 30, 2026UNKNOWN OR OTHER
I noticed a "ticking" noise a few years ago, it wasn't that bad and while taking my truck to the dealer for an oil change I ask about it and the representative told me that in this models that was normal. Since it wasn't that bad and the truck didn't show any problems at that time, I just decide to let it be. This weekend I took my family out of state for a fun trip, and while going in the highway around 55-65 miles per hour, the truck suddenly lose power, it felt like it the truck "sits" the cars behind me had to dodge me and I lost control of the truck and had to steer to the right getting out of the highway and almost go into a ditch, thankfully nothing scaleted to a big and disastrous accident. The engine light started to flash. And suddenly stopped, I turn off the truck checked back for my family and after a few minutes, I started the truck again, the truck started right away and but I noticed the "ticking" got a little louder, talking to my neighbor about this he told me he had the same issue and hes motor went bad and they said it was a bad AFM system causing this, I started searching on line for it and see there been the same issues with the AFM with other drivers, and seen that the have the same issues Im confident that it is an AFM problem. Truck is been running and is my daily work car and I notice is loosing power, I contacted the dealer but haven't had any answer yet. I cant take it to a mechanic shop because they would charge me in between 2,500 to 5k to fixed, money that I dont have, while in the call with one shop he told me about this place to put a claim and notify about how dangerous this can be if in a highway.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747528June 30, 2026ENGINE, FUEL/PROPULSION SYSTEM
Lifters (the part that opens and closes engine valves) fail prematurely. There was a loud ticking noises, rough idling. Took to dealership and they advise that yes the lifters are failing and not drivable at this time.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747534June 30, 2026ELECTRICAL SYSTEM, ENGINE, STEERING
My 2024 GMC Sierra Denali Ultimate 1500 experienced a catastrophic powertrain failure that created a serious safety hazard. On XXX, while driving at highway speeds, the truck unexpectedly shifted into neutral, causing an immediate loss of propulsion. During this event, the electrical system was also affected. The battery power dropped, power steering assistance was lost, and due to the electronic push-button start system, the vehicle could not be restarted while in this condition. This placed me and surrounding motorists at significant risk of a crash. I initially brought the vehicle to Point GMC, where I was advised no issue was found. After the problem continued, I returned on XXX and a dealership technician rode with me. During the test drive on [XXX], the truck again shifted into neutral, confirming the defect. The vehicle was then towed to the dealership, where diagnostics revealed DTC P0016. I was informed the engine had seized and required a complete engine replacement. The engine was replaced by an authorized GMC dealership in New Jersey. After only about 2,000 miles, the check engine light returned and the vehicle began experiencing additional electrical issues. This is a Denali Ultimate, the highest trim level, with advanced electronic systems, making these recurring failures especially concerning. To date, the vehicle has been inspected by three authorized GMC dealerships, and I have opened multiple cases with GMC Corporate. Despite repeated repair attempts, the manufacturer has not provided a permanent resolution. I continue to experience recurring engine and electrical issues and no longer have confidence in the safety or reliability of this vehicle. Given the repeated failures, loss of propulsion, loss of steering assistance, inability to restart the vehicle, and lack of resolution after multiple dealership visits and an engine replacement, I believe this matter warrants investigation by NHTSA. 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
- #11747094June 29, 2026BACK OVER PREVENTION: WARNINGS
I bought my 2026 GMC in April. Several times the audio doesn't work work. When this happens audio related safety technology is affected too including turn signal sounds and back camera audio also. A person walking behind the truck can be seen on the screen but no warning beeps are heard. When backing up the warning for getting too close to an object also doesn't work. I called the dealer in early May and was told that this was a known issue and that it needed a software update. took the truck to the dealer on May 8th and the software update was performed. When the update had been completed when I started the truck after the update there was no audio. I told the service advisor it was currently happening and she took it back to the technician. They disconnected the battery cables to reset the system and told me to do that in the future until the issue is resolved. I opened Case #100978480 with GM on June 1st because I wanted to be sure that GM was also informed of the issue. I was hoping they would be proactive and report back to me what they were doing to resolve this issue. Instead I was told that I need to call the dealer and the dealer would call GM because an update might be available but dealers wouldn't be informed and wouldn't check unless I called.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747117June 29, 2026STRUCTURE:BODY
I was driving down the highway and the front Upper Grille Deflector flew off while at highway speeds. Due to the nature of being on a highly congested bridge, the grill piece flying off could've seriously injured not only myself, but other motorist around me. There is currently a GM recall (N242490120) out however, it only affects the 2022 model trucks. This makes no sense as this issue has been reported via threads and discussions on the internet for 2023 year models like mine numerous times. This is a serious issue and should be recalled just like the 2022 models. Not only am I now paying for a manufactuer defect out of pocket, but who's to say that the "new" part doesn't do the same thing and either I or another motorist is seriously injured or worse...killed.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0
- #11747167June 29, 2026ENGINE
Engine knocking. Engine being replaced under warranty due to premature bearing failure. Picotest was performed prior to my purchase with 12800 miles. 0w40 oil being used at the time of failure. At the dealer now getting the engine replaced.
- Crash:
- No
- Fire:
- No
- Injuries:
- 0
- Deaths:
- 0