Is the 2021 GMC Sierra 1500 a bad year?
603 owner complaints to NHTSA. Engine complaints: 372, 37× a quiet Sierra 1500 year.
Keep it, but watch the engine
The engine draws 37× the complaints of a quiet Sierra 1500 year, but the 2021 is still young: half of its engine complaints so far came in by 59k miles, and that mark will move as owners add miles. Check your powertrain warranty first.
The verdict moves with mileage: the same car reads differently at 30,000 and at 150,000 miles.
What 2021 Sierra 1500 owners report, by mileage
Each system owners named in five or more complaints, with the mileage range where the middle half of those complaints were filed. Read at 59,000 miles.
| SYSTEM | COMPLAINTS | MIDDLE HALF FILED AT | TYPICAL US REPAIR BILLS |
|---|---|---|---|
| EngineSTANDS OUT | 371 (62%) | 34k–96k miles · around this mileage | Valve cover gasket replacement $110–$500 · Timing chain replacement $1,000–$4,000 |
| Transmission and drivetrainSTANDS OUT | 147 (24%) | 35k–104k miles · around this mileage | CV axle / CV joint replacement (one side) $300–$1,500 · Automatic transmission replacement $2,500–$7,000 |
| Electrical system | 76 (13%) | 3k–63k miles · around this mileage | 12-volt battery replacement $100–$400 · Starter motor replacement $350–$1,200 |
| Steering | 35 (6%) | 4k–56k miles · mostly behind | — |
| Brakes | 25 (4%) | 5k–44k miles · mostly behind | — |
| Fuel system | 42 (7%) | too few with a mileage | — |
| Body structure | 13 (2%) | too few with a mileage | — |
| Latches and locks | 10 (2%) | too few with a mileage | — |
| Suspension | 10 (2%) | too few with a mileage | — |
| Lane assist | 8 (1%) | too few with a mileage | — |
| Speed control | 7 (1%) | too few with a mileage | — |
| Visibility and wipers | 7 (1%) | too few with a mileage | — |
| Air bags | 6 (1%) | too few with a mileage | — |
| Collision avoidance | 6 (1%) | too few with a mileage | — |
Bills are typical US ranges from the sources named in the tool (J.D. Power, Kelley Blue Book, CarParts.com and others), printed only for systems that stand out or sit at or ahead of 59,000 miles. Not a quote.
What owners reported alongside their complaints
Of 603 complaints: 6 mention a crash · 6 mention a fire · 3 report an injury · 34 say the car was towed.
230 complaints were filed in the last 12 months, the newest in Nov 2026.
Counts of what owners wrote in their complaints, not verified by anyone.
Recalls for the 2021 GMC Sierra 1500: 7
The transmission control valve may fail and cause the rear wheels to lock up. Rear wheel lock up increases the risk of a crash.
The connecting rod and/or crankshaft engine components may have manufacturing defects that can lead to engine damage and engine failure. Engine failure increases the risk of a crash.
The transmission control valve may fail and cause the rear wheels to lock-up. Rear wheel lock-up can increase the risk of a crash.
The 17" spare tire provided with the vehicle is not compatible for use with the accessory wheels, which can cause the anti-lock brake system (ABS) to not function properly under certain conditions. An ABS system that does not function properly can increase the risk of a crash.
Incorrect bolts may have been used at one or more fastening locations to secure the seat belts to the vehicle. If an incorrect bolt was used, the seat belt may not be properly attached to the vehicle. If a seat belt assembly is not properly attached to the vehicle, the seat belt may not properly restrain an occupant in the event of a crash, increasing the risk of injury.
The seat belt brackets may not be secured to the seat frame in the front-row center seating position. If a seat-belt bracket is not secured, the seat belt may not properly restrain an occupant in the front-row center seat position, increasing the risk of injury in a crash.
The vehicles may have been manufactured with Continental tires that were overcured. Overcured tires may experience a carcass break in the sidewall resulting in a sudden air loss or could develop a belt edge separation which could lead to partial or full tread/belt loss. Either condition increases the risk of a crash.
A recall may cover only some cars of a model year; the campaign size counts every model and year it lists. Enter your VIN at nhtsa.gov/recalls: dealers fix open recalls free.
Service bulletins from GMC: 577
Repair instructions GMC sent its dealers for symptoms seen in the shop on the 2021 GMC Sierra 1500. Ask a dealer or mechanic for a bulletin by its number.
This document assists GM dealer technicians with diagnosing torque converter concerns to ensure torque converter replacement is necessary
The document advise technicians after an engine repair involving removal of the camshaft actuators…
Possibility of DTC p0011 p0016 and potential for a rattle or ticking noise to occur from the Intake Cam Actuator…
Some vehicles may have a condition where the connecting rod and/or crankshaft engine components in these vehicles may have manufacturing defects that can lead…
NHTSA defect investigations: 5
Loss of motive power due to engine failure post recall remedy
Loss of motive power due to engine failure post recall remedy
Loss of motive power due to engine failure
Loss of motive power due to engine failure
Air Bag Malfunction
Neighbouring years
2020 Sierra 1500: 484 complaints, keep it, but watch the engine · 2022 Sierra 1500: 606 complaints, keep it, but watch the engine.
Every GMC Sierra 1500 year
2000 · 2001 · 2002 · 2003 · 2004 · 2005 · 2006 · 2007 · 2008 · 2009 · 2010 · 2011 · 2012 · 2013 · 2014 · 2015 · 2016 · 2017 · 2018 · 2019 · 2020 · 2021 · 2022 · 2023 · 2024 · 2025 · 2026 · All Sierra 1500 years side by side
Other GMC models: GMC Acadia · GMC Canyon · GMC Denali · GMC Envoy · GMC Envoy XL · GMC Envoy Xuv · GMC Jimmy · GMC Safari · GMC Savana · GMC Sierra · GMC Sierra 2500 · GMC Sierra 3500 · GMC Sierra Denali · GMC Sonoma · GMC Terrain · GMC Yukon · GMC Yukon Denali · GMC Yukon Denali XL · GMC Yukon XL · GMC Yukon XL 1500. All makes and models.
Questions
Is the 2021 GMC Sierra 1500 a bad year?
603 owner complaints to NHTSA. Engine complaints: 372, 37× a quiet Sierra 1500 year. At 59,000 miles the tool says: Keep it, but watch the engine. The engine draws 37× the complaints of a quiet Sierra 1500 year, but the 2021 is still young: half of its engine complaints so far came in by 59k miles, and that mark will move as owners add miles. Check your powertrain warranty first.
What are the most common problems with the 2021 GMC Sierra 1500?
By owner complaints to NHTSA: engine (371), transmission and drivetrain (147), electrical system (76), steering (35), brakes (25). Half of the engine complaints were filed between 34k–95k miles.
How many recalls does the 2021 GMC Sierra 1500 have?
7 recall campaigns list this model year: Transmission and drivetrain (NHTSA 26V-083), Engine (NHTSA 25V-274), Transmission and drivetrain (NHTSA 24V-797), Tires (NHTSA 21V-985) and more. A recall may cover only some cars; check by VIN at nhtsa.gov/recalls.
Method: counts of unverified owner complaints filed with NHTSA, compared only with other years of the same model (sales volumes are unknown, so no failure rate is computed). A system stands out at 40+ complaints and at least twice the model's quiet (lower-quartile) year, or twice the share across every vehicle of that model year. The mileage range is the 25th to 75th percentile of the mileages owners reported. Data received by NHTSA through November 5, 2026. Repair prices are typical US ranges from named sources, not quotes. Not a diagnosis and not financial advice. PulsCar is not affiliated with NHTSA. Check this car at your own mileage.