The 2024 GMC Terrain rides on GM's third-gen platform with turbocharged four-cylinders, but it's too new for pattern failures — we're seeing isolated catastrophic engine problems on certain units that suggest manufacturing defects rather than design flaws. The transmission cooler and drivetrain mount issues are carryovers from prior gen.
Catastrophic 1.5L Turbo Engine Failures (Connecting Rod/Piston/Bearings)
Rare · high severityTypical onset: 5,000-30,000 mi
Symptoms: Sudden knocking or rattling from engine bay under load, Metal shavings in oil during early oil changes, Check engine light with misfire codes (P0300-series), Complete loss of power or engine seizure
Fix: Short block replacement or complete engine swap under warranty; outside warranty this is 18-24 labor hours plus engine assembly. These are isolated build-quality issues — bad bearing clearances, defective pistons, or oil starvation from assembly debris — not wear items.
Estimated cost: $8,000-12,000
Transmission Oil Cooler Line Leaks
Occasional · medium severityTypical onset: 40,000-70,000 mi
Symptoms: Red ATF puddles under vehicle near radiator area, Transmission overheating warnings on dash, Burnt transmission fluid smell, Harsh or delayed shifts when fluid is low
Fix: Replace cooler lines and fittings where they connect to radiator/transmission; 2.5-3.5 hours labor. Often the quick-connect fittings crack from heat cycling. Catch it early before transmission damage occurs.
Estimated cost: $400-700
Transmission Mount Failure (Torque Strut)
Occasional · low severityTypical onset: 50,000-80,000 mi
Symptoms: Clunking when shifting from park to drive or reverse, Excessive engine movement visible from engine bay during acceleration, Vibration through cabin at idle, Drivetrain 'rocking' sensation during throttle tip-in
Fix: Replace upper transmission mount (torque strut); 1.5-2 hours labor. The hydraulic damping fails and the rubber tears. Simple job but ignore it and you'll accelerate wear on CV axles and other mounts.
Estimated cost: $250-450
Fuel Filter Clogging (Particulate Issues)
Occasional · medium severitySymptoms: Rough idle and hesitation under acceleration, Engine stumbling or cutting out at highway speeds, Hard starting after sitting overnight, P0087 code (fuel rail pressure too low)
Fix: Replace in-tank fuel pump module with filter; 2-3 hours labor because tank often needs dropping. We're seeing contaminated fuel or manufacturing debris in tanks on some early '24s. Not a design issue but a quality control slip.
Estimated cost: $500-900
Head Gasket Weeping (1.5L Turbo)
Rare · medium severityTypical onset: 20,000-50,000 mi
Symptoms: White residue around head/block mating surface, Slow coolant loss without visible external leaks, Sweet smell from engine bay after heat cycling, No overheating or performance loss initially
Fix: Head gasket replacement; 8-10 hours labor including resurfacing. We've seen a handful where torque specs weren't met during assembly or gasket material is defective. Catch it early before coolant gets into oil or combustion chambers.
Estimated cost: $1,800-2,800
Skip the 2024 model year entirely — let early adopters work out the quality control gremlins; by 2025-26 these assembly issues should be resolved, but right now you're gambling on whether your unit came off the line on a good day.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.