The 2018 Legacy is a solid midsize sedan, but the CVT transmission and head gasket issues on the 2.5L remain the platform's Achilles' heels. The 3.6L H6 is notably more reliable but thirstier and harder to find used.
CVT Transmission Judder and Premature Failure
Common · high severityTypical onset: 60,000-100,000 mi
Symptoms: Shuddering or hesitation during acceleration from a stop, Whining or grinding noises under load, Harsh engagement when shifting into Drive or Reverse, Transmission overheat warnings on highway drives or towing
Fix: CVT replacement or rebuilt unit installation is typical; oil cooler often replaced simultaneously (common failure point). Expect 8-12 hours labor for CVT swap. Some owners opt for external cooler upgrades to extend life.
Estimated cost: $4,500-7,000
Head Gasket Leaks (2.5L H4 Only)
Occasional · high severityTypical onset: 80,000-130,000 mi
Symptoms: External oil seepage around cylinder head seams, Coolant loss without visible leaks (internal seepage), White smoke from exhaust on cold starts, Overheating under sustained load or climbing grades
Fix: Full head gasket replacement on both banks requires engine removal or heavy disassembly. Expect 16-20 hours labor. Smart shops resurface heads and replace timing components, water pump, and all seals while in. Not an issue on the 3.6L H6.
Estimated cost: $2,800-4,200
Piston Ring Land Failure and Oil Consumption (2.5L)
Occasional · high severityTypical onset: 50,000-90,000 mi
Symptoms: Excessive oil consumption (1 quart per 1,000-2,000 miles), Blue smoke from exhaust under acceleration, Fouled spark plugs and misfires, Loss of power and rough idle
Fix: Requires short-block replacement or full engine rebuild with new pistons, rings, and bearings. Some owners opt for used low-mileage engines. Expect 18-24 hours labor for short-block swap. This is a known FB25 design flaw from 2011-2019 models.
Estimated cost: $4,000-6,500
Fuel Pump Failure (Recall-Related)
Occasional · high severitySymptoms: No-start condition or long crank time, Engine stalling at idle or low speeds, Hesitation or stumbling under acceleration, Fuel pump whine audible from rear seat area
Fix: Covered under NHTSA recall if not yet performed; dealer replaces impeller-type fuel pump assembly. If out of recall window, indie shops charge 2-3 hours labor for pump replacement. Check recall status by VIN before buying.
Estimated cost: $800-1,200
Transmission Mount Failures
Common · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Clunking or banging when shifting into gear, Excessive vibration at idle in Drive, Visible sagging or movement of transmission case, Increased cabin NVH (noise/vibration/harshness)
Fix: Rear transmission mount (pitch stopper) wears quickly due to CVT torque characteristics. Replacement is straightforward: 1.5-2 hours labor. OEM mounts recommended over aftermarket for longevity.
Estimated cost: $250-450
Eyesight Camera Calibration Drift
Occasional · low severitySymptoms: Pre-collision braking warnings with no obstacles present, Lane-keep assist disengaging randomly, Adaptive cruise control refusing to activate, Eyesight warning light illuminated on dash
Fix: Windshield replacement or even minor impacts can knock cameras out of alignment. Dealer-level recalibration required (1-1.5 hours). Some shops have ADAS calibration rigs, but many owners report needing dealer visit.
Estimated cost: $150-350
Buy a 3.6L H6 if you can find one; otherwise, expect to budget $1,500-2,000/year for CVT and engine-related repairs on the 2.5L past 80k miles.
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.