Faulty lifters replaced on passenger side. Had only 25000 miles on engine. GM extended warranty on thousands with this engine but not mine. Have only 28000 miles on truck and just turned 5th year so warranty is void. GM should extend warranty on all vehicles with this engine.
2021 GMC Sierra engine problems
moderate 199 complaints filed with NHTSA · avg repair $3,100
Complaints
199
Recalls
0
Crashes
0
Avg fix
$3,100
What owners are reporting 8 most recent
TRAVELING ON INTERSTATE GOING AT THE POSTED SPEED LIMIT AND TURNED OFF THE INTERSTATE ONTO MY EXIT TURN AND VEHICLE ENGINE STARTED KNOCKING AND ENGINE SHUT OFF OIL WARNING LIGHT CAME ON ALL WHILE TRYING TO STOP THE VEHICLE AT THE CROSS TRAFFICE STOP SIGHN AND ENDED UP STOPPED IN THE MIDDLE OF ANOTHER HIGHWAY BARLEY MISSING THE CROSS TRAFFIC COMING AT ME FROM BOTH DIRECTIONS. THIS HAPPENED AT I94 A…
Famous lifter issue in the l84 engine. Hundreds of documented complaints and current class action lawsuit. I had to stop on a busy highway and it caused unsafe passing and irritated humans.
Complete engine power loss.
The contact owns a 2021 GMC Sierra 1500. The contact stated while driving 15 MPH and making a turn, the vehicle lost power steering assist functionality. Additionally, the brake pedal was depressed several times but failed to respond. The parking brake, traction control, brake, engine, and headlights warning lights were illuminated. The contact also stated that the warning message "Limited Power" …
mechanical and electrical issues with my GMC Sierra Elevation Duramax Diesel, purchased in 2021. Despite multiple dealership visits, diagnostic evaluations, repairs, and software updates, these issues persist and have significantly impacted the reliability and safety of the vehicle. In December 2025, my vehicle was taken to the dealership for diagnostics and a third software update intended to re…
15000 MILES LIFTER FAILURE IN TRAFFIC HIGHWAY AT SPEED 70 MPH LOST POWER ENGINE FAILED MULTILANE HIGHWAY RUSH HOUR TRAFFIC NO WARNING FAILURE
THE VEHICLE WAS BOUGHT BRAND NEW AND WAS ONLY DRIVEN FOR A WEEK. IT WAS IN MOTION ON THE FREEWAY WHEN THE ENGINE STARTED TO SOUND NOISIER THAN USUAL, LIKE THAT OF AN OLDER TRUCK. IT WAS HARD TO NOTICE ON HIGHER SPEEDS ON THE FREEWAY, BUT UPON SLOWING DOWN ON CURVES, IT GOT MORE OBVIOUS THAT SOMETHING WAS REALLY WRONG BECAUSE THE NOISE SOUNDED LIKE SOMETHING WAS LOOSE INSIDE THE ENGINE. THERE WA…
Common questions
How serious is the engine problem on the 2021 GMC Sierra?
It's a documented issue but not catastrophic. 199 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Mileage data is limited for this issue. Owners report failures across a wide range, suggesting cause is more about driving conditions and maintenance than mileage alone.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Other problem areas on this vehicle
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Severity ratings are derived from reported crashes, fires, injuries, and fatalities.
Repair cost estimates are independent-shop national averages and may differ in your area.
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