Used GMC Terrain 2nd Gen (2018–2024): Buyer's Guide

The 2018 GMC Terrain filed 208 NHTSA complaints in its first model year and drew 5 safety recalls, one for a high-pressure fuel pump that could separate and cause a fuel leak, another for a driveshaft that could fracture. The 2021 Terrain filed 31 complaints and drew 2 recalls, both minor. Same platform. Same sheet metal. The difference is what three years of production sorting does to a new design.

That gap makes generation year the single most important variable when buying a 2nd gen Terrain. But there is a second variable that most buyers miss: the powertrain contraction. This generation launched with three engine options: a turbocharged four, a turbocharged diesel, and a more powerful turbo four. It ended with one. If you want the stronger 2.0T engine or the diesel, you have exactly two model years to choose from.

Here is what the NHTSA database, owner forums at terrainforum.net, and real ownership data say before you spend $15,000 to $30,000 on one.

This Generation at a Glance

The 2nd gen Terrain launched for 2018 on GM's D2XX platform, shared with the Chevrolet Equinox and Buick Envision. It was a complete redesign from the previous generation: smaller footprint, lighter weight, and all-new turbocharged engines replacing the outgoing 2.4L and 3.6L naturally aspirated options.

The notable difference from the platform twin Equinox: the Terrain gets a 9-speed automatic transmission (9T50 or 9T65 depending on engine), while the Equinox 1.5T runs a 6-speed. That 9-speed causes its own issues, covered below.

A mid-cycle refresh arrived for 2022. GMC reshaped the exterior with a new grille, full LED lighting front and rear, and introduced the AT4 off-road trim. Wireless Apple CarPlay and Android Auto became standard. The Denali gained a head-up display option.

The 2025 marks the start of a 3rd generation Terrain with a new platform.

Market pages: 2018 · 2019 · 2020 · 2021 · 2022 · 2023 · 2024

Powertrain and Trim Breakdown

1.5L Turbo (2018–2024)

The 1.5T is the engine you will find in the overwhelming majority of used 2nd gen Terrains. From 2021 onwards, it is the only engine offered. It pairs with the 9T50 9-speed automatic in FWD or AWD configurations.

What owners like: At its best, the 1.5T is smooth and efficient: 26 to 28 mpg combined is real-world achievable. The ride quality on the 2nd gen Terrain is notably better than the Equinox despite the shared platform, and the 1.5T's outputs feel adequate for daily driving.

9T50 transmission hesitation. The 9-speed transmission is the most consistently reported complaint from 1.5T owners across Terrain and Equinox owner forums. At speeds between 15 and 35 mph, the transmission hunts between gears and produces a hesitation that feels like driving a manual in the wrong gear. Cold-weather conditions and stop-and-go traffic make it worse. GM has issued TSBs addressing this, and a TCM reflash at the dealer often reduces the behavior significantly. If a Terrain you are test driving has this symptom at low speed, ask the dealer to pull codes and check for open TSBs before purchase. Transmission rebuild or replacement if the issue progresses: $4,000 to $7,000.

High-pressure fuel pump recall (2018 only). NHTSA Campaign 18V358000 covers 2018 Terrain and other GM vehicles for a high-pressure fuel pump whose weld could crack and separate. A separated pump allows the fuel line to vibrate against the engine bay, causing a fuel leak and potential fire. GM's fix is replacement of the HPFP and high-pressure fuel pipe. Verify this is complete on any 2018 you consider.

StabiliTrak warnings. The "Service StabiliTrak" warning paired with reduced engine power is the most common electrical complaint on all 2nd gen model years. In most cases, the culprit is a failing wheel speed sensor or steering angle sensor. The warning can cause the vehicle to limit power output, which is alarming but usually not catastrophic. Replacement wheel speed sensors run $80 to $200 each. Clearing codes at a shop and monitoring is the first step before replacing parts.

Cold-weather performance. GM Authority noted in 2022 that small-displacement turbocharged engines on this platform can lose noticeable performance in extreme cold due to turbo efficiency loss and oil thickening. Forum posts from northern-state owners consistently mention this, particularly on the 1.5T. Not a mechanical failure, but relevant if you are buying in a cold climate.

Carbon buildup (GDI engine). The LYX uses direct injection, which means intake valves don't get washed by fuel. Carbon accumulates on the intake valves over time, causing rough idle and misfires. This shows up on vehicles with 80,000 to 120,000 miles that haven't had walnut blasting or intake cleaning. The fix runs $300 to $600 at an independent shop.

Turbo seal. Turbo failures on the 1.5T are not common before 100,000 miles, but forum threads document cases in the 80,000 to 120,000 mile range. Oil burning preceding turbo failure (2+ quarts between changes) is the early warning sign. If a Terrain is consuming oil noticeably, have the turbo and PCV system inspected before committing. Turbo replacement runs $1,200 to $2,200.

Model-year note. The 2018 and 2019 1.5T models are mechanically the same but carry more open recall risk. The 2020-on 1.5T benefits from three years of production refinement and has a cleaner recall history.

2.0L Turbo (2018–2020 Only)

The 2.0T was available in SLE and SLT trims as an option and came standard in the Denali. It pairs with the 9T65 9-speed automatic. GM dropped the 2.0T for 2021 without explanation, though the Terrain saw roughly a 33% sales drop the same year, suggesting the engine was a significant draw.

What owners like: Forum consensus on the 2.0T is clear. Owners who drove both engines consistently prefer the 2.0T. The 252 hp and 260 lb-ft of torque are meaningfully different from the 1.5T in highway merging and loaded driving. It's the engine this platform was designed around.

Vacuum pump. The 2.0T LTG uses a mechanical vacuum pump to maintain brake booster function. Forum threads on terrainforum.net document vacuum pump failures producing a grinding or rattling sound at startup. In worse cases, metal fragments contaminated the engine. A new OEM vacuum pump runs about $150 to $200 as a preventive replacement. An engine with confirmed metal contamination from a failed pump requires significantly more expensive repair. Pull the oil cap on any 2.0T and look for metal flakes or evidence of debris.

Transmission turbine shaft. CarComplaints.com documents at least one case of the turbine shaft inside the 9T65 transmission breaking without warning. This is not a widespread pattern but warrants a thorough inspection. Listen for any whining or grinding from the transmission during the test drive.

Reliability at mileage. Multiple forum members report 80,000 to 130,000 miles on 2.0T models with no major issues beyond normal maintenance. The 2.0T appears to be the more durable choice within this generation, and used pricing does not always reflect that premium. If you find a 2019 or 2020 SLT or Denali with the 2.0T and documented maintenance, it's the sweet spot buy in this generation.

Model-year notes. The 2018 2.0T carries additional recall risk (same as 1.5T: HPFP, driveshaft). The 2019 adds a seat weld insufficiency recall on the right rear. The 2020 2.0T is the cleanest: 2 recalls (start/stop accumulator, LATCH anchor), 169 NHTSA complaints. It's the last year you can get this engine.

1.6L Turbo Diesel (2018–2019 Only)

The diesel was a two-year offering before GM discontinued it after 2019. It's the outlier in this generation: best fuel economy, lowest power, and a distinct set of problems that didn't affect the gasoline engines.

What the diesel does well: Real-world combined fuel economy of 32 mpg, matching or exceeding many compact hybrids. The diesel's 240 lb-ft of torque arrives low in the RPM range, making it feel more responsive around town than its 137 hp suggests.

Catalytic converter failure. Diesel Terrain owners on forum threads report DPF (diesel particulate filter) and catalytic converter failures at 100,000 to 110,000 miles. GM extended the emissions warranty on some 2018 and 2019 diesel models to 100,000 miles specifically because of this pattern. After 100k, owners are on their own for a part that dealers in some cases couldn't source due to discontinued supply.

Turbo failure. One forum member documented a turbo replacement on a 2018 diesel at 60,000 miles. The diesel turbo runs at higher temperatures than the gasoline turbos and is more sensitive to oil maintenance intervals.

Parts availability. The diesel was discontinued after two model years. This isn't catastrophic; GM still services these engines. But emissions-specific parts including EGR components and the DPF are increasingly difficult to source. This is relevant for high-mileage purchases.

Verdict on the diesel: Avoid unless you have a specific reason to want it (high annual mileage, documented full service history, verified warranty repairs completed). The fuel savings do not offset the elevated repair risk after 100,000 miles and the parts sourcing challenges.

Trim-Specific Notes

The 2018–2021 Terrain came in four trims: SL, SLE, SLT, and Denali. The 2022–2024 refresh added AT4 and dropped the SL base.

SL (2018–2021): Base trim. FWD only in most configurations. 1.5T only. No option for 2.0T or diesel. Missing the driver assistance tech that became standard in 2020 on higher trims. Hard to recommend for used buyers when SLE and SLT prices aren't much higher.

SLE (2018–2024): The most common trim on the used market. Adds automatic emergency braking and forward collision alert, which were standard from 2020 in all trims. Pre-2020 SLE models may lack these. Check the window sticker or VIN on any pre-2020 purchase to confirm feature presence.

SLT (2018–2024): Adds heated front seats, leather seating, and technology that most buyers actually want. Best value point in the lineup for used buyers who want comfort without the Denali premium.

Denali (2018–2024): Came standard with the 2.0T through 2020. This is the trim to search if you specifically want the 2.0T without engine option hunting. From 2021 on, Denali was downgraded to 1.5T with no upgrade option. Denali from 2021+ offers luxury content but the same engine as the base. The 2022+ Denali adds the available head-up display. If you are looking at a Denali 2021 or later, know you are paying a luxury premium for trim, not powertrain.

AT4 (2022–2024): New trim for the 2022 refresh. Standard AWD, front skid plate, all-terrain tires, recovery hooks. Priced between SLT and Denali. Genuine light off-road capability for mild trails and snowy roads. The AT4 is what the Terrain AT4X would be if this platform had the clearance for it. It doesn't. AT4 is soft-road; it handles loose pavement, light mud, and snow better than the standard Terrain but isn't a Jeep replacement.

Which Model Years to Target

2018 and 2019: The launch years of this generation carry disproportionate risk. Five recalls on the 2018 alone include a fire-risk fuel pump and a driveshaft that could fracture. The 2019 adds three fires in the NHTSA complaints data. Both years may be fine with all recalls completed, but you have more to verify. Budget extra time for a VIN-level recall check and dealer confirmation of completion.

2020: The cleanest year for the 2.0T. Two recalls, both minor. Still has both gasoline engines available. If you want the 2.0T without taking on 2018-2019 recall risk, this is the year.

2021: Fewest complaints of the generation (31). Two minor recalls. J.D. Power rated this Terrain second in compact SUVs for 2021. The catch: 1.5T only. If the engine limitation doesn't matter to you, the 2021 is the most sorted version of this platform.

2022: The refresh year brings wireless CarPlay and the AT4 trim but also a fuel pump stall recall affecting 23,164 vehicles. Parts were unavailable for several months after the recall was issued, and some owners reported recurring failures after replacement. Verify the recall (NHTSA 23V013000) is completed on any 2022 purchase.

2023 and 2024: Low complaint counts, one or two minor recalls each. The 2024 has a door striker fracture recall covering all four door strikers. Verify completion before purchase. Newer year but limited used inventory and pricing closer to new.

Overall recommendation: 2020 if you want the 2.0T. 2021 if you're fine with the 1.5T and prioritize reliability track record. Either way, run the VIN before you buy.

Pre-Purchase Inspection Checklist

These are specific to the 2nd gen Terrain. Skip the generic "check the tires" advice. A mechanic can do that. These are the items you can verify yourself during the test drive and seller conversation.

For all model years:

• Run the VIN through CarScout's recall lookup before the test drive. Verify every open recall has a completion date.
• Start the engine cold. Listen for any ticking or rattling that fades as the engine warms. If it doesn't fade within two minutes, flag it.
• During the test drive, accelerate to 20–25 mph with light throttle. The transmission should shift smoothly. Any herky-jerky hunting or hesitation between 15 and 35 mph is the 9T50 adaptation issue.
• Note whether the "Service StabiliTrak" or "Engine Power Reduced" warnings appear on the instrument cluster. If yes, have a shop scan OBD codes before proceeding.
• Test the infotainment by entering navigation, playing audio, and pairing a phone. Spontaneous reboots or a blank screen are documented issues that may require module replacement.

For 2018 models specifically:

• Confirm NHTSA recall 18V358000 (high-pressure fuel pump) is completed. This is a fire risk. No completion date, no purchase.
• Confirm recall for driveshaft fracture is also completed. Check the VIN at gmc.com/ownercenter/recalls.

For 2.0T models (2018–2020):

• Remove the oil cap. Look for metallic debris or an unusual amount of gunk. Either is a sign of vacuum pump contamination.
• During the test drive, listen for any grinding or metallic sound on startup that changes with RPM. Vacuum pump failure sounds like this.
• Ask for oil change records. The 2.0T is sensitive to extended intervals.

For diesel models (2018–2019):

• Ask for DPF and catalytic converter service history.
• Confirm the catalytic converter has been serviced or replaced. If it's original at 100,000+ miles with no documented service, budget $800 to $1,500 for replacement parts if available.
• Check exhaust for excessive black or white smoke, which can indicate DPF saturation or injector issues.

For 2022 models:

• Sit in the driver's seat and apply sideways pressure. A loose or squeaky seat may indicate the driver's seat bolt recall (22V724000) hasn't been completed.
• Confirm NHTSA fuel pump recall 23V013000 is completed. If the seller says it hasn't been done yet, the repair is free at the dealer. Verify parts are now available before assuming it can be completed quickly.

For 2024 models:

• Confirm the door striker fracture recall is completed on all four doors.

Running Costs

Annual repair cost (RepairPal): $558 average for Terrain, compared to $521 for the compact SUV segment and $652 for all vehicles. Lower than average for the class.

Oil changes: GM's Oil Life Monitor triggers at 7,500-mile intervals with full synthetic 0W-20. Forum members recommend not stretching the OLM to the maximum on the 1.5T or 2.0T; 5,000-mile intervals are a reasonable buffer for turbo engine longevity.

Transmission service: The 9T50 and 9T65 don't have a manufacturer-required fluid change interval, but independent mechanics and forum consensus recommend a fluid flush at 60,000 to 80,000 miles as preventive maintenance, particularly on vehicles with documented hesitation issues.

Transmission rebuild: If the 9T50 or 9T65 requires rebuild or replacement, expect $4,000 to $7,000 at an independent shop. A TCM reflash ($100 to $200 dealer fee) is always the first step before assuming major transmission work is needed.

FAQ

Is the 2nd gen GMC Terrain reliable? For 2020 and later model years, yes. RepairPal rates the Terrain at 3.5 out of 5 for reliability and calculates an average annual repair cost of $558, below the compact SUV average. The 2021 logged just 31 NHTSA complaints. The 2018 and 2019 carry significantly more recall risk and should be verified carefully before purchase.

What year 2nd gen GMC Terrain should I avoid? The 2018 is the most problematic model year within this generation, with 5 safety recalls including a fire-risk fuel pump weld failure (NHTSA 18V358000) and a driveshaft fracture recall. The 2019 is also worth approaching carefully: it drew 171 complaints and 3 fires in NHTSA data. Both years can be fine if all recalls are documented as complete, but they require more verification.

Is the 2.0T worth hunting for over the 1.5T? Yes, if you plan to keep the vehicle past 80,000 miles. The 2.0T delivers 252 hp versus 170 hp, a difference you feel in daily driving. Forum owners who drove both engines consistently prefer the 2.0T. The catch: it was only available 2018–2020. Denali trims through 2020 came standard with the 2.0T, making a used 2019 or 2020 Denali the most direct route to finding one.

Should I buy a diesel GMC Terrain? Only if the maintenance history is complete and documented. The 1.6T diesel offers exceptional fuel economy: 32 mpg combined. It was discontinued after 2019 for a reason. Catalytic converter failures past 100,000 miles are a documented pattern. Parts sourcing is increasingly difficult. For most buyers, the risk profile of a high-mileage diesel Terrain is not worth the fuel savings.

How many miles does a 2nd gen GMC Terrain last? With consistent oil changes and basic maintenance, the 2nd gen Terrain regularly reaches 150,000 to 200,000 miles. Forum threads at terrainforum.net document multiple owners at 130,000 to 180,000 miles with no major mechanical failures, primarily on 2020–2022 models with the 1.5T. The 2.0T appears similarly durable with proper maintenance.

Bottom Line

The 2020 and 2021 are the buys here. The 2020 is the last year for the 2.0T and carries only two minor recalls. The 2021 is the most refined 1.5T version with just 31 NHTSA complaints for the year. Both represent a sorted product after three years of launch-year issues.

Avoid the 2018 unless every recall is documented closed. Be cautious on 2019. Verify the fuel pump recall on any 2022.

Run every VIN through a recall check before you show up to test drive. CarScout members can set up scouts on specific years, trims, and price ranges at usecarscout.com to track price drops on the exact configuration you're looking for.

Data sourced from NHTSA recalls database, EPA fuel economy ratings, CarScout market data, and real owner experiences from terrainforum.net, CarComplaints.com, and RepairPal owner reports. See the full GMC Terrain market data for current inventory and pricing.