The 2015 Forester with the naturally-aspirated 2.5L FB25 is generally reliable, but the platform suffers from head gasket seepage issues inherited from earlier EJ engines (though less catastrophic), CVT cooler line failures, and oil consumption problems that can grenade motors if ignored.
CVT Transmission Oil Cooler Line Failure
Common · high severityTypical onset: 60,000-110,000 mi
Symptoms: Transmission fluid dripping or pooling under vehicle, Burnt smell from overheating CVT fluid, Transmission overheating warning light, Sudden loss of drive with complete fluid loss
Fix: Replace oil cooler lines and seals; often requires dropping the subframe for access. 3-5 hours labor depending on whether subframe removal is needed. Refill CVT fluid and check for internal damage.
Estimated cost: $800-1,500
Excessive Oil Consumption (FB25 Engine)
Common · high severityTypical onset: 50,000-90,000 mi
Symptoms: Low oil warning light between changes, Burning 1+ quart per 1,000 miles, Blue smoke on cold starts or acceleration, Fouled spark plugs
Fix: Root cause is piston ring design and cylinder glazing. Subaru extended warranty covered some cases. Fix requires full short block replacement or engine rebuild with updated pistons/rings. 18-24 hours labor for short block swap.
Estimated cost: $4,500-7,000
Head Gasket Seepage
Occasional · medium severityTypical onset: 80,000-140,000 mi
Symptoms: External coolant weeping at head/block mating surface, Slight coolant smell after driving, Minor drops or staining on driveway, Slow coolant loss without visible leaks elsewhere
Fix: Not the catastrophic internal failures of older EJ engines, but external seepage is common. Requires head removal, resurfacing, new gaskets, timing components. 12-16 hours labor for both sides.
Estimated cost: $2,500-3,800
Brake Light Switch Failure
Common · medium severitySymptoms: Brake lights stay on constantly, Brake lights don't illuminate when pedal pressed, Cruise control won't engage or disengage, Push-button start may not work, Shift interlock problems (can't shift out of park)
Fix: Simple switch replacement above brake pedal. Subject to recall but many vehicles fall outside VIN range. 0.5 hours labor.
Estimated cost: $150-250
Rear Wheel Bearing Noise
Occasional · medium severityTypical onset: 70,000-120,000 mi
Symptoms: Humming or growling from rear that increases with speed, Noise changes with cornering, May feel vibration through seat
Fix: Replace rear hub/bearing assembly. AWD vehicles eat bearings faster with mismatched tires or deferred maintenance. 1.5-2 hours per side.
Estimated cost: $350-550 per side
Turbo Wastegate Rattle (2.0XT Models Only)
Occasional · low severityTypical onset: 40,000-80,000 mi
Symptoms: Rattling noise from engine bay at idle or light throttle, Noise disappears under boost, No performance loss initially
Fix: Wastegate actuator arm wears and creates play. Can lead to boost control issues if ignored. Turbo replacement or actuator rebuild required. 6-8 hours labor for turbo R&R.
Estimated cost: $1,800-2,800
Solid daily driver if oil consumption hasn't started and CVT has been maintained, but budget $1,500-2,000 for deferred issues on higher-mileage examples — avoid any burning oil.
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.