2024 GMC Sierra 1500: What to check before buying

The 6.2L engine seizes or shuts off without warning, often at highway speed. Reports describe rod knock, failed crankshaft bearings, and oil filters full of metal. Most failures land between 10,000 and 20,000 miles, but some come within days of delivery. Several engines fail a few hundred miles after passing the recall 25V274000 inspection. Replacement engines can take weeks or months to arrive. One stall ended in a crash with an injury. Diesel owners report a separate problem: exhaust drone and heavy vibration under acceleration, traced to broken exhaust bracket studs.

Most of these reports are about recall 25V274000, not new failures. Owners say parts for the repair are unavailable, dealers keep rescheduling, and the wait has gone on too long. Many have not had a failure yet. Some trucks stall at around 70 mph and need a new engine. Others lose power with a clanking sound after passing the recall inspection. A few owners report low oil, oil pressure warnings, heavy oil use, and metal shavings in the filter.

The 10-speed transmission loses reverse, refuses to shift, or drops into a "Reduced Acceleration" limp mode. Dealers trace many of these to a faulty valve body, usually between about 4,775 and 10,672 miles. Replacement valve bodies are often back-ordered, leaving trucks parked for weeks. Some trucks lose power at highway speed and won't restart, which matches the engine failures. Other reports describe a truck rolling backward on an incline after being shut off in park, injuring the driver, and a truck shifting into reverse on its own with nobody inside.

The truck shuts down while moving, and in some cases power steering assist, the dash, and the hazard lights cut out too. Dealers sometimes swap the fuse block or starter before finding a seized engine. Other reports describe glitches: blank instrument clusters, black or frozen infotainment screens, no chimes or turn-signal sound, windows dropping over bumps, locks cycling, and washers spraying on their own. False automatic braking caused one injury. Diesel trucks go into limp mode in single-digit cold when DEF sensors freeze, with a countdown to a 55 mph limit.

The upper grille molding comes loose at highway speeds of 65 to 75 mph and flies off. It can crack or scratch the windshield or damage the hood. Reports cluster between about 27,500 and 36,700 miles, and some trucks lose the piece twice. Owners note that recall 25V060000 covers the 2022 model but not this year. The power tailgate also opens on its own while driving, often after a bump, with no warning, and cargo falls out. Some dealers offer only to disable the power tailgate. One owner reports a windshield leak that led to mold.

Backing up at night is the main complaint. The sealed LED reverse lights are too dim and aimed too high to light the area behind the truck. In dark places, the backup camera and camera mirror show little beyond the red guide lines. Small objects and children are hard or impossible to see. The lights can't be adjusted or serviced. Dealers call it a design issue or check it in a lit garage and find nothing. A couple of reports in this category actually describe engine ticking and stalls.

Only a few reports, but they are serious. One describes the truck accelerating when the brake was pressed and then the pedal going to the floor, ending in a low-speed rear-end crash. Another describes a brake system failure warning, along with steering lock and stability control alerts, that left the truck barely able to stop. Other problems include unexplained uneven pad wear with repeated brake jobs within 30,000 miles, sudden braking from 55 to 30 mph for a parked car, and trailer brake disconnect messages that come and go.

The driver-assist systems fail in both directions. In one case, automatic emergency braking did not activate at low speed and the truck rear-ended another vehicle at 500 miles. In another, the truck braked hard at highway speed with a crash alert, even though nothing was ahead, and then would not accelerate. Super Cruise is reported to cross double yellow lines and swerve during lane changes after a May 2025 software update. Pressing the Resume button can also make the truck accelerate from a near stop.

Few reports, but one is severe: a front wheel came off at 50 to 55 mph, injuring the driver and totaling the truck, with damage to the ball joint and hub bearing. In another case, a rear shock was found blown and leaking within the first day of ownership. A third truck made a metal-on-metal noise after a highway bump, and a dealer found loose, improperly attached differential and rear axle supports. That repair was denied under warranty.