The 2009 Legacy is generally reliable, but the 2.5L four-cylinder is notorious for external head gasket leaks, and the 4EAT/5EAT automatics can develop torque converter shudder. The 3.0L H6 is far more durable but rare to find.
External Head Gasket Leak (2.5L H4 only)
Common · medium severityTypical onset: 80,000-120,000 mi
Symptoms: Coolant seepage visible on engine block below heads, Sweet smell after engine warms up, Gradual coolant loss without overheating, Oil-soaked areas around lower timing covers
Fix: Both head gaskets, timing components, water pump, all seals. 12-15 labor hours; do it once and properly or plan to repeat in 60k mi.
Estimated cost: $2,200-3,200
Torque Converter Shudder (4EAT/5EAT Automatics)
Occasional · medium severityTypical onset: 100,000-150,000 mi
Symptoms: Vibration or shudder between 35-45 mph under light throttle, Feels like driving over rumble strips, Worsens when transmission is hot, Fluid may smell burnt even if level is correct
Fix: Flush with Subaru High Torque ATF first (1 hr), may buy 20-40k mi. Eventual torque converter replacement requires transmission removal: 8-10 labor hours.
Estimated cost: $1,800-2,800
Front Wheel Bearing Failure
Common · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Growling or humming that increases with speed, Noise changes pitch in turns, ABS/VDC lights may illuminate intermittently, Play detectable when wheel is rocked by hand
Fix: Hub/bearing assembly replacement per side, 1.5-2 hours each. Often one side fails, other follows within 20k mi.
Estimated cost: $350-550 per side
Transmission Oil Cooler Line Corrosion
Occasional · high severityTypical onset: 90,000-140,000 mi
Symptoms: ATF dripping from front of vehicle near radiator, Rust visible on steel cooler lines at crimped joints, Sudden transmission slipping if major leak occurs, ATF level drops noticeably between checks
Fix: Replace both hard lines and flex hoses to/from radiator. 2-3 labor hours; catch early before transmission runs dry and self-destructs.
Estimated cost: $450-750
Rear Differential Carrier Bearing Whine
Occasional · low severityTypical onset: 120,000-180,000 mi
Symptoms: High-pitched whine from rear, speed-dependent, Most noticeable on deceleration, Noise present in all gears, not affected by clutch (MT) or shifter position (AT), Differential fluid may have metal shavings
Fix: Carrier bearing replacement requires diff teardown, preload setting: 4-6 hours. Confirm with fluid inspection before committing.
Estimated cost: $900-1,400
Ignition Switch Recall Failure (Post-Repair)
Rare · high severitySymptoms: Engine dies while driving without warning, All dash lights go dark suddenly, Key may become stuck in ignition, No crank, no start intermittently
Fix: Check for open recall (WTK-85); even post-repair switches can fail. Replacement is 1-2 hours at dealer or indie shop familiar with steering column disassembly.
Estimated cost: $300-600 if out of warranty
Solid daily driver if you budget for head gaskets on the 2.5L or hunt down the rarer 3.0L H6; avoid high-mileage examples with no service records on the transmission.
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.