Owners have reported 10 crashes, 1 fire and 5 injuries to NHTSA for the 2018 GMC Sierra 1500. These are unverified owner reports, not confirmed defect rates.
Owner complaints111
POWER TRAIN
Owners of the 2018 GMC Sierra 1500 frequently report issues with the vehicle's power train, particularly involving the transmission and torque converter. Common symptoms include hard shifting, shuddering, jerking, and loss of power, often occurring around the 30,000 to 125,000-mile range. Multiple complaints describe the transmission failing to engage properly, causing the vehicle to hesitate or accelerate unpredictably, which has led to crashes and injuries in some cases. Issues with the 8-speed transmission, especially related to the valve body and torque converter, are mentioned repeatedly, with several owners indicating that these problems persist even after repairs. Potential buyers should be aware of these patterns and consider the safety implications, especially in relation to the transmission's performance and reliability.
Severity signals: 4 crash, 0 fire, 3 injury reports
Owner complaints33
ENGINE
Owners report frequent issues with the 2018 GMC Sierra 1500's engine, particularly involving lifter and camshaft failures. Complaints frequently mention symptoms such as loud ticking noises, engine misfires, sudden power loss, and excessive oil consumption. These issues often occur around 58,000 to 120,000 miles, with some cases requiring costly engine replacements. Multiple owners describe safety implications, including unexpected engine shutdowns and loss of power at highway speeds, which could pose risks during driving. Additionally, injector failures leading to misfires and engine mount problems are also noted, highlighting potential reliability concerns for prospective buyers.
Owner complaints30
ELECTRICAL SYSTEM
Owners of the 2018 GMC Sierra 1500 frequently report issues with the electrical system, particularly involving the trailer brake system, which triggers persistent warning messages and alerts. Complaints often describe problems with the vehicle's wiring harness, including exposure and arcing of wires, as well as damage potentially caused by soy-based wire coatings attracting rodents. Some owners note repeated battery replacements and instances where the vehicle unexpectedly shuts off or loses power while driving. A notable safety concern is a reported vehicle fire while parked, and several complaints mention the vehicle's electrical malfunctions leading to significant inconvenience and potential hazards. These issues appear across a range of mileages, with some occurring shortly after purchase and others at higher mileages, such as 128,000 miles.
Severity signals: 0 crash, 1 fire, 0 injury reports
Owner complaints26
STEERING
Owners of the 2018 GMC Sierra 1500 frequently report issues with the electric power steering system, often describing sudden loss of power steering while driving, which makes the vehicle difficult to maneuver. Symptoms commonly include the steering wheel becoming firm or jerking unexpectedly, with some reports noting complete electrical failure affecting other systems like brakes and dashboard electronics. These issues are often reported at various mileage points, with some occurring as early as 15,000 miles. One complaint involves a crash due to a suspension failure that led to loss of control. Potential buyers should be aware of these safety implications, as loss of steering control can pose significant risks.
Severity signals: 1 crash, 0 fire, 0 injury reports
Owner complaints20
SERVICE BRAKES
Owners of the 2018 GMC Sierra 1500 frequently report issues with the brake system, particularly related to the brake assist and vacuum pump. Common symptoms include a vibrating or soft brake pedal, increased effort required to stop, and extended braking distances. Many complaints also mention persistent service alerts for the trailer brake system, even when not towing. These issues are often noted at mileages ranging from approximately 37,000 to 135,000 miles. Safety implications include difficulty in stopping the vehicle, which poses a risk of collisions, especially in situations requiring sudden braking. Buyers should be aware of these potential brake-related issues when considering this vehicle model.
Owner complaints15
UNKNOWN OR OTHER
Owners of the 2018 GMC Sierra 1500 frequently report issues with the vehicle's transmission, describing symptoms such as shaking, shuddering, and rough shifting, often around 45,000 to 80,000 miles. Air conditioning failures, specifically with the condenser, are also noted, with some reports around 48,000 miles. Additionally, multiple complaints highlight problems with the vehicle's brake system, including stiff brake pedals and reduced braking power. Safety concerns are evident, as one owner reports a crash due to the vehicle surging unexpectedly. Other issues include spontaneous glass breakage, such as shattered sunroofs and rear windows, which may pose additional safety risks. These reported problems provide potential buyers with insight into recurring issues and mileage points where they might expect similar failures.
Severity signals: 1 crash, 0 fire, 0 injury reports
Owner complaints6
ENGINE AND ENGINE COOLING
Owners of the 2018 GMC Sierra 1500 report several engine-related issues, predominantly involving engine performance and internal component failures. Common symptoms include violent shaking at startup, abnormal ticking or banging noises, hesitation during acceleration, and reduced power messages. Multiple complaints highlight discoveries of metal shavings in the engine, often leading to recommendations for engine replacement. These issues typically emerge at mileages ranging from approximately 64,000 to 169,000 miles. While no direct safety incidents such as crashes or fires are reported, symptoms like stalling and failure to accelerate could potentially affect driving safety. Buyers considering this model should be aware of these potential engine concerns, particularly at higher mileages.
Owner complaints5
AIR BAGS
Owners of the 2018 GMC Sierra 1500 report several issues with the airbag system. Some complaints describe unexpected airbag deployment, such as side airbags deploying at low speeds without a crash, while others report airbags not deploying during collisions, including at speeds around 35 mph, resulting in injuries. One owner notes a deployment during a deer collision at 75 mph, leading to injury from the steering wheel cover. Several incidents involve crashes, and two injuries are reported. The issues occur at various mileages, with one owner noting a failure at approximately 25,000 miles. Buyers should be aware of potential airbag deployment failures and associated safety risks.
Severity signals: 3 crash, 0 fire, 2 injury reports
Owner complaints4
STRUCTURE
Owners of the 2018 GMC Sierra 1500 frequently report issues with the sunroof, describing incidents where the sunroof explodes outward while driving, resulting in glass shards entering the cabin. This problem occurs under various conditions, such as on highways and neighborhood streets, with no external impact or weather-related causes noted. Additionally, there is a report of a spare tire falling from the vehicle due to a broken crank cable, posing a risk of road debris. One complaint involves a crash related to brake pedal difficulty, but this is not directly linked to structural issues. These incidents occur at varying mileages, with some vehicles nearing the end of their warranty period. Safety implications include potential injury from flying glass and road hazards from dislodged vehicle parts.
Severity signals: 1 crash, 0 fire, 0 injury reports
Owner complaints2
VEHICLE SPEED CONTROL
Owners of the 2018 GMC Sierra 1500 report issues with vehicle speed control, primarily involving transmission and engine power concerns. Common symptoms include the truck failing to accelerate properly, high RPMs without gear shifting, and vibrations from the rear end. Additionally, some vehicles unexpectedly enter Reduced Engine Power mode, causing the vehicle to slow down abruptly, which is particularly concerning in heavy traffic situations. These issues are noted around the 31,000-mile mark and sometimes persist even after component replacements such as throttle body sensors and accelerator pedal assemblies. Safety implications include the potential difficulty in maneuvering through traffic due to sudden deceleration.
