2020 GMC Sierra 1500: Engine complaints
Owner-reported issue (NHTSA complaints, not a recall)
Symptoms
NHTSA has 255 owner complaints for the 2020 GMC Sierra 1500 that list the engine component. Complaints are individual owner reports, not verified defects.
Examples:
- NHTSA complaint ODI #11771297 (filed 10/15/2026): “Driving down road started to hear a weird growling knocking sound and noticed a reduction of power. also noticed lower then normal oil pressure. changed oil found metal shavings in the oil. sent to chevy dealership. diagnosed "rod bearing failure" needs new engine.…”
- NHTSA complaint ODI #11770786 (filed 10/13/2026): “The contact owns a 2020 gmc sierra 1500. the contact stated that while driving at an undisclosed speed, the vehicle suddenly entered limp mode without warning. the vehicle was taken to the dealer, where the computer was reflashed and the vehicle temporarily returned to normal operation; however, the…”
- NHTSA complaint ODI #11769874 (filed 10/08/2026): “I have a 2020 gmc sierra 1500 at4 with the l87 6.2l v8. the cam shaft and lifters have failed for a 2nd time. the first time happened in 2022. it was under warranty and happened at approximately 40,000 miles. this last time it happened in 2026 and was at 125,000 miles - both for the same thing -…”
Likely causes
These complaints do not establish a single root cause; read the examples above and get a diagnosis.
Fix, in plain English
No single fix is established by these reports. Check your VIN for open recalls at nhtsa.gov/recalls, ask a dealer about technical service bulletins (TSBs) or extended warranty coverage, then have the system diagnosed.
DIY difficulty: Pro
Internal engine work (lifters, oil consumption, fuel dilution diagnosis) requires engine teardown or dealer software/tests. (Our assessment.)
Cost
No sourced cost range for this issue. Get a written quote after diagnosis.
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