I started to notice changes in performance around 75k miles. Seemed like performance was subpar compared to what was the norm. Seemed to lose some power. Minimal at first, more so just recently around 90k. Oil consumption was starting to accelerate at each oil change at 75k, 80k, 85k, 90k. To the point around 85k and 90k that I would not go over even 1 mile from the 5k threshold without changing t…
2020 GMC Sierra engine problems
moderate 146 complaints filed with NHTSA · avg repair $3,100
Complaints
146
Recalls
0
Crashes
0
Avg fix
$3,100
What owners are reporting 5 most recent
The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving approximately 35 MPH, the vehicle lost automotive power with the check engine warning light illuminated and the message "Vehicle Might Lose Power" displayed. The vehicle remained at the residence, and the contact used a self-diagnostic tool to retrieve a fault code related to the coolant valve D. The contact determined …
Fuel management system caused a lifter to fail (stuck) which resulted in camshaft damage at 77,611 miles. GM refused to cover the repair, although there is a pending class action lawsuit against GM for this very issue. Truck was repaired at a GM dealership - Sunrise Collierville, TN. Repair costs was approximately $7,000. This occurred during a 2.5 hour road trip which put lives at risk. The truck…
In December of 2023 my 2020 GMC Sierra 1500 was driving down the freeway, experienced a jerking and low oil pressure. Pulled over and shut vehicle off and wouldn't turn back on, engine locked up. The vehicle received a brand new 6.2l replacement motor in April of 2024- $15k in parts and labor. This vehicle was not included in the recent recall, but obviously experienced a similar issue. This was a…
Engine lost all power while driving highway speed. Vehicle towed to Cavender Chevrolet dealer in Boerne, TX. Dealer inspected and determined cam bearings damaged. Engine replaced with remanufactured engine.
Common questions
How serious is the engine problem on the 2020 GMC Sierra?
It's a documented issue but not catastrophic. 146 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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