2021 GMC Sierra 1500
The 2021 GMC Sierra 1500 is a popular full-size pickup truck known for its comfortable ride, upscale interior options, and strong towing capabilities. Engine options include a 2.7L turbocharged inline-4 producing 310 hp and 348 lb-ft of torque, a 5.3L EcoTec3 V8 producing 355 hp and 383 lb-ft of torque, a 6.2L EcoTec3 V8 producing 420 hp and 460 lb-ft of torque, and a 3.0L Duramax turbo-diesel inline-6 producing 277 hp and 460 lb-ft of torque. Transmission options depend on the engine but include 6-speed, 8-speed, and 10-speed automatic transmissions. Common praises for the Sierra include its quiet cabin and user-friendly infotainment system. Criticisms often focus on the price relative to competitors and some perceived quality issues.
Engine
2.7L Turbocharged Inline-4
- Piston Failure
- Description/Symptoms: Some owners have reported piston failure, sometimes with little to no warning. Symptoms can include a sudden loss of power, loud knocking or tapping noises from the engine, excessive oil consumption, and potentially a check engine light. Often occurs with the 2021-2022 model years.
- Solution: Engine replacement is typically required if the piston has failed catastrophically. Repair options may be available in some instances.
- Estimated Cost to Fix: $7,000 - $10,000+
- Recalls: None Found
5.3L EcoTec3 V8
- Active Fuel Management (AFM)/Dynamic Fuel Management (DFM) Lifter Failure
- Description/Symptoms: The AFM/DFM system deactivates cylinders to improve fuel economy. However, the lifters associated with this system can fail, leading to misfires, rough running, and a check engine light. Ticking or knocking noises from the engine are also common.
- Solution: Replacing the failed lifters and potentially the camshaft is the common fix. Some owners opt to delete the AFM/DFM system altogether to prevent future issues.
- Estimated Cost to Fix: $3,000 - $6,000+ depending on the extent of the damage and if AFM/DFM is deleted.
- Recalls: None Found
- Excessive Oil Consumption
- Description/Symptoms: Some owners have reported higher than expected oil consumption, requiring frequent top-offs between oil changes.
- Solution: Repair options include piston ring replacement, valve seal replacement, or, in severe cases, engine replacement.
- Estimated Cost to Fix: $1,500 - $7,000+ depending on the repair needed.
- Recalls: None Found
6.2L EcoTec3 V8
- Active Fuel Management (AFM)/Dynamic Fuel Management (DFM) Lifter Failure
- Description/Symptoms: Same as the 5.3L V8 engine issues. The AFM/DFM system deactivates cylinders to improve fuel economy. However, the lifters associated with this system can fail, leading to misfires, rough running, and a check engine light. Ticking or knocking noises from the engine are also common.
- Solution: Replacing the failed lifters and potentially the camshaft is the common fix. Some owners opt to delete the AFM/DFM system altogether to prevent future issues.
- Estimated Cost to Fix: $3,000 - $6,000+ depending on the extent of the damage and if AFM/DFM is deleted.
- Recalls: None Found
3.0L Duramax Turbo-Diesel Inline-6
- No Issues Found
Transmission
6-Speed Automatic
- No Issues Found
8-Speed Automatic (Specifically the 8L90)
- Rough Shifting/Hard Shifts
- Description/Symptoms: Hesitation when shifting, hard or clunky shifts (especially between 1st and 2nd gear), and shuddering.
- Solution: Software re-programming has been used to fix this issue.
- Estimated Cost to Fix: $100 - $200+ for software re-programming.
- Recalls: None Found
10-Speed Automatic
- Rough Shifting/Hesitation
- Description/Symptoms: Some owners have reported occasional rough shifting or hesitation, particularly during low-speed driving.
- Solution: Transmission recalibration or fluid flush may resolve the issue.
- Estimated Cost to Fix: $100 - $500
- Recalls: None Found
Suspension
- Vibration Issues
- Description/Symptoms: Some owners have reported experiencing vibrations, especially at highway speeds. This can be caused by several factors including tire balance, wheel alignment, or issues with the driveshaft.
- Solution: Addressing the root cause of the vibration, such as rebalancing tires, performing a wheel alignment, or replacing the driveshaft.
- Estimated Cost to Fix: $100 - $1,000+ depending on the repair needed.
- Recalls: None Found
Electrical
- Infotainment System Glitches
- Description/Symptoms: Freezing, lagging, or unresponsive touchscreen, Bluetooth connectivity issues, and problems with Apple CarPlay/Android Auto.
- Solution: Software updates, resetting the infotainment system, or, in some cases, replacing the infotainment unit.
- Estimated Cost to Fix: $0 (software update) - $1,500+ (infotainment unit replacement).
- Recalls: None Found
- Battery Drain Issues
- Description/Symptoms: Premature battery drain, especially if the vehicle sits for an extended period.
- Solution: Diagnosing and addressing the source of the parasitic draw. This could involve replacing the battery, fixing a faulty electrical component, or performing a software update.
- Estimated Cost to Fix: $100 - $500+ depending on the cause.
- Recalls: None Found
Exterior
- Bed Bounce/Vibration
- Description/Symptoms: A noticeable “bounce” or vibration felt in the truck bed, especially on certain road surfaces. This issue is not exclusive to the 2021 model year.
- Solution: There is no definitive fix for this issue. Some owners have reported improvements after installing aftermarket suspension components or adding weight to the bed.
- Estimated Cost to Fix: Varies greatly depending on the attempted solution.
- Recalls: None Found
Interior
- No Issues Found
Summary
The 2021 GMC Sierra 1500 can be a good vehicle, but some issues are common across different engine and transmission configurations. The 2.7L Turbo engine has potential piston issues, while the 5.3L and 6.2L V8 engines are prone to AFM/DFM lifter failure, leading to costly repairs. Transmission problems, especially with the 8-speed, and electrical glitches can also be frustrating. While some fixes are relatively inexpensive, major engine or transmission repairs can be quite costly. Potential buyers should be aware of these issues and carefully inspect the vehicle’s service history before making a purchase.