This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
full bulletin at NHTSA ↗2021 GMC Terrain engine problems
moderate Owners of the 2021 GMC Terrain have filed 4 NHTSA complaints about the engine at roughly $3,100 to repair (U.S. federal records, as of August 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
Complaints
4
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2017 Terrain | 57 |
| 2018 Terrain | 18 |
| 2019 Terrain | 17 |
| 2020 Terrain | 18 |
| 2021 Terrain (this page) | 4 |
| 2022 Terrain | 7 |
| 2023 Terrain | 5 |
| 2024 Terrain | 4 |
What stands out
Of the 15 model years of GMC Terrain we track for engine problems, this one has the fewest owner complaints on file (4).
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
full bulletin at NHTSA ↗This service bulletin provides information to dealership personnel for new vehicles with less than 1,000 miles that may not pass California smog inspection or smog inspection in other states.
full bulletin at NHTSA ↗This warranty administration bulletin provides policy information on vehicles outside of a California Emissions State who move to and register their vehicle in a California Emission State may be entitled to the 7 year, 70,000-mile Emission Select State Component Limited Warranty.
full bulletin at NHTSA ↗This service bulletin provides a procedure to replace the FPDCM if found to cause customers concerns of Crank No Start, Stalling, Malfunction Indicator Lamp (MIL) Illuminated – DTC P023F or P129F Set.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 0 most recent
Had engine trouble with your 2021 GMC Terrain?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2021 GMC Terrain?
It's a documented issue but not catastrophic. 4 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.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2021/GMC/Terrain.
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. Some links on this page are affiliate links.