2021 GMC Sierra
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 choices include a 2.7L turbocharged four-cylinder (310 hp, 348 lb-ft torque), a 5.3L EcoTec3 V8 (355 hp, 383 lb-ft torque), a 6.2L EcoTec3 V8 (420 hp, 460 lb-ft torque), and a 3.0L Duramax turbodiesel (277 hp, 460 lb-ft torque). Transmission options vary depending on the engine, including 6-speed, 8-speed, and 10-speed automatics. Owners often praise the Sierra for its refined cabin and advanced technology, but some common complaints revolve around electrical glitches, transmission performance (particularly with the 8-speed), and some build quality issues.
Engine
2.7L Turbocharged Four-Cylinder
- Piston Failure
- Description/Symptoms: Engine knocking, loss of power, potential engine failure. Premature wear and cracking of the pistons, often attributed to detonation or pre-ignition.
- Solution: Engine replacement, often covered under warranty if the issue occurs within the warranty period.
- Estimated Cost to Fix: $7,000 - $9,000+
- Recalls: None Found
5.3L EcoTec3 V8
- Active Fuel Management (AFM)/Dynamic Fuel Management (DFM) Lifter Failure
- Description/Symptoms: Ticking noise from the engine, misfires, loss of power, check engine light. Can lead to camshaft damage.
- Solution: Replacement of the affected lifters and potentially the camshaft. AFM/DFM delete kits are also sometimes used to prevent recurrence.
- Estimated Cost to Fix: $2,500 - $5,000+
- Recalls: None Found
- Oil Consumption
- Description/Symptoms: Noticeable decrease in oil level between oil changes, blue smoke from the exhaust.
- Solution: Possible piston ring replacement, valve seal repair, or PCV valve replacement. In some cases, a complete engine rebuild or replacement is necessary.
- Estimated Cost to Fix: $1,000 - $7,000+ (depending on the severity and repair required)
- Recalls: None Found
6.2L EcoTec3 V8
- Active Fuel Management (AFM)/Dynamic Fuel Management (DFM) Lifter Failure
- Description/Symptoms: Ticking noise from the engine, misfires, loss of power, check engine light. Can lead to camshaft damage.
- Solution: Replacement of the affected lifters and potentially the camshaft. AFM/DFM delete kits are also sometimes used to prevent recurrence.
- Estimated Cost to Fix: $2,500 - $5,000+
- Recalls: None Found
- Oil Consumption
- Description/Symptoms: Noticeable decrease in oil level between oil changes, blue smoke from the exhaust.
- Solution: Possible piston ring replacement, valve seal repair, or PCV valve replacement. In some cases, a complete engine rebuild or replacement is necessary.
- Estimated Cost to Fix: $1,000 - $7,000+ (depending on the severity and repair required)
- Recalls: None Found
3.0L Duramax Turbodiesel
- Fuel Injector Failure
- Description/Symptoms: Rough idling, loss of power, excessive smoke from the exhaust.
- Solution: Replacement of the faulty fuel injector(s).
- Estimated Cost to Fix: $800 - $2,000+ (depending on how many injectors need replaced)
- Recalls: None Found
Transmission
8-Speed Automatic (8L90)
- Harsh Shifting/Hesitation
- Description/Symptoms: Noticeable clunking or hard shifts, especially between 1st and 2nd gear. Hesitation when accelerating.
- Solution: Transmission flush and fluid replacement with an updated fluid formula. In some cases, valve body replacement or transmission rebuild.
- Estimated Cost to Fix: $300 - $5,000+ (depending on severity)
- Recalls: None Found
10-Speed Automatic (10L80)
- Harsh Shifting/Hesitation
- Description/Symptoms: Noticeable clunking or hard shifts, especially between 1st and 2nd gear. Hesitation when accelerating.
- Solution: Transmission flush and fluid replacement with an updated fluid formula. In some cases, valve body replacement or transmission rebuild.
- Estimated Cost to Fix: $300 - $5,000+ (depending on severity)
- Recalls: None Found
Suspension
- No Issues Found
Electrical
- Infotainment System Freezing/Lagging
- Description/Symptoms: Infotainment screen freezes, slow response to touch inputs, system reboots unexpectedly.
- Solution: Software update to the infotainment system, replacement of the infotainment unit.
- Estimated Cost to Fix: $0 - $1,500+ (depending on whether it is software or hardware)
- Recalls: None Found
- Backup Camera Failure
- Description/Symptoms: Backup camera displays a black screen or distorted image.
- Solution: Check camera connections, replace the backup camera unit.
- Estimated Cost to Fix: $200 - $500+
- Recalls: None Found
Exterior
- Bed Rail Corrosion
- Description/Symptoms: Rust forming along the bed rails, particularly in areas with harsh weather conditions.
- Solution: Rust removal, repair, and repainting of the affected areas. Application of protective coatings.
- Estimated Cost to Fix: $300 - $1,000+ (depending on severity)
- Recalls: None Found
- Tailgate Malfunction
- Description/Symptoms: Tailgate fails to open or close properly, electric tailgate not working.
- Solution: Repair or replacement of the tailgate latch mechanism, wiring harness, or electric motor.
- Estimated Cost to Fix: $200 - $800+
- Recalls: None Found
Interior
- Seat Heater Malfunction
- Description/Symptoms: Seat heaters fail to turn on or provide inadequate heat.
- Solution: Replacement of the heating element or control module.
- Estimated Cost to Fix: $200 - $600+
- Recalls: None Found
Summary
The 2021 GMC Sierra 1500 presents a mix of potential issues ranging from moderate to severe. Engine problems like AFM/DFM lifter failure and oil consumption in the V8 engines can lead to significant repair costs. Transmission issues such as harsh shifting are also relatively common, especially in the 8-speed and 10-speed automatic transmissions. Electrical glitches with the infotainment system and backup camera can be annoying but are generally less expensive to fix. Exterior problems like bed rail corrosion can occur, particularly in certain climates. Overall, potential buyers should be aware of these common issues and consider extended warranties or thorough pre-purchase inspections to mitigate potential repair costs.