The 2005 Forester with the 2.5L naturally-aspirated EJ253 engine is generally reliable but notorious for head gasket failure, which dominates the ownership experience. Transmission issues and oil leaks are secondary concerns that surface as these vehicles age past 100k miles.
External Head Gasket Failure (EJ253 Engine)
Common · medium severityTypical onset: 90,000-150,000 mi
Symptoms: Oil seepage visible on lower engine block sides near cylinder heads, Coolant drips from head gasket area (less common than oil leaks on this generation), White exhaust smoke on cold start if coolant enters combustion chamber, Coolant or oil level dropping slowly over time
Fix: Replace both head gaskets, resurface heads if warped, new timing belt/water pump/thermostat while apart. 12-16 labor hours at independent shop. Many owners opt for upgraded MLS gaskets to prevent repeat failure.
Estimated cost: $1,800-2,800
Automatic Transmission Failure (4EAT)
Occasional · high severityTypical onset: 150,000-200,000 mi
Symptoms: Delayed engagement when shifting into Drive or Reverse, Harsh or slipping shifts between 2nd and 3rd gear, Transmission fluid contamination (metal particles visible), Torque bind on tight turns (AWD system binding)
Fix: Torque converter or valve body rebuild may delay full replacement. Transmission replacement (remanufactured) takes 8-10 hours. External oil cooler lines and cooler itself often fail, causing fluid contamination and accelerating internal damage.
Estimated cost: $2,500-4,200
Transmission Oil Cooler Line Corrosion
Common · medium severityTypical onset: 120,000-180,000 mi
Symptoms: ATF leaking near radiator or under front of vehicle, Transmission running hotter than normal, Rust perforation on steel cooler lines where they route near crossmember, Low transmission fluid level on dipstick
Fix: Replace corroded steel lines with OEM or aftermarket. Often done preventively during head gasket job. 2-3 hours labor if done standalone. Salt-belt cars see this earlier and more severely.
Estimated cost: $250-500
Front Lower Control Arm Bushing Deterioration
Common · low severityTypical onset: 80,000-130,000 mi
Symptoms: Clunking over bumps from front suspension, Steering wander or vague on-center feel, Inner front tire wear if alignment pulled out of spec, Visible cracking or tearing of rubber bushings on inspection
Fix: Replace front lower control arms (bushings not sold separately by Subaru). 2-3 hours labor both sides. Alignment required after. One NHTSA recall addressed premature corrosion/cracking on some units.
Estimated cost: $400-700
Rear Wheel Bearing Failure
Occasional · medium severityTypical onset: 100,000-160,000 mi
Symptoms: Growling or humming noise from rear that increases with speed, Noise changes pitch in turns (louder on one side), Vibration felt through seat at highway speeds, Excessive play when wheel is rocked by hand (wheels off ground)
Fix: Replace rear wheel bearing hub assembly, one side at a time as they fail. 1.5-2 hours per side. Not a press-in bearing; hub assembly bolts on, making this easier than many vehicles.
Estimated cost: $250-400 per side
Exhaust System Rot (Rust Belt)
Common · low severityTypical onset: 80,000-120,000 mi
Symptoms: Exhaust drone or louder-than-normal sound, Visible rust perforation on muffler, resonator, or pipes, Exhaust smell in cabin with HVAC on fresh air, Rattling from heat shields or loose hangers
Fix: Cat-back or axle-back exhaust replacement common in salt states. OEM Subaru parts rust quickly; aftermarket stainless options last longer. 1.5-2.5 hours labor depending on what's replaced.
Estimated cost: $400-900
Buy it if the head gaskets have been done recently with upgraded parts and the transmission shifts cleanly; budget $2k-3k for deferred maintenance if they haven't, and avoid high-mileage examples with unknown service history.
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.