Subaru Forester Common Problems & Reliability Guide

EJ25 engines are notorious for head gasket failures, especially external coolant leaks. Symptoms include coolant smell from engine bay, dropping coolant levels, and coolant/oil mixing in severe cases. Often occurs between 80,000-150,000 miles.

Hot exhaust makes wiring harnesses brittle and road debris can damage sensors and wiring. Coolant contamination from leaking head gaskets can leave silica deposits that damage sensors. Very common issue across all model years.

EJ25 engines use timing belts that must be replaced at 105,000 miles or earlier if signs of wear. Belt failure can cause catastrophic engine damage as these are interference engines.

P0420 is one of the most common codes on this generation. Can be caused by failed converter, oxygen sensor issues, or upstream engine problems like misfires. Forester has high occurrence rating for P0420.

EJ25 engines tend to burn more oil due to worn piston rings and stuck oil scraper rings. Owners should check oil levels regularly and top off between changes.

EJ25 engines in 2009-2010 models continue to have head gasket issues at higher mileage. Coolant smell from engine compartment and dropping coolant levels are warning signs. 2011+ models with FB25 engine largely resolved this issue.

2011+ Foresters with FB25 engine have complaints about excessive oil consumption. Subaru issued bulletin 02-157-14R and repaired some engines under warranty. Owners should monitor oil levels closely.

2009-2010 turbocharged EJ255 models require timing belt replacement at 105,000 miles. 2011+ non-turbo models with FB25 have timing chains that can fail at higher mileage but don't require regular replacement.

P0420 codes remain very common. Often requires replacing front O2 sensor and/or catalytic converter. Upstream misfires and lean/rich conditions accelerate catalyst degradation.

Ignition coils prone to failure, especially in wet weather. Symptoms include misfires, rough running, and check engine light. Preventive replacement recommended around 100,000 miles.

Failure-prone CVT transmissions are the biggest issue. Some fail at 20,000 miles, others at 120,000+ miles. Symptoms include jerking, shuddering, revving without acceleration, or slow acceleration. Subaru extended warranty to 10 years/100,000 miles for all 2014-2018 Foresters.

2.5L FB25 engines continue to burn excessive oil due to design issues. Subaru faced class-action lawsuit. Owners must check oil frequently and top off between changes. Worst on 2014 models.

CVT control unit solenoid problems, especially after head gasket failures. Repair costs around $2,400 at dealerships. Often related to broader CVT reliability issues.

Faulty rear suspension springs can break, affecting ride quality and handling. Subaru recalled vehicles manufactured March 2013-October 2018 for this issue.

Wheel bearings wear out prematurely, causing humming or grinding noises and vibration. More common on earlier model years (2014-2015).

Some 2014 models experienced head gasket failures with associated problems like bad solenoids. Repair costs can reach $7,500 or more for complete engine work.

2019-2020 models prone to windshields cracking from small chips. Multiple owner complaints about fragile windshields requiring early replacement.

Reports of vehicles stalling while driving without warning. Potentially related to electronic throttle control or fuel system issues. Safety concern requiring immediate attention.

Batteries draining prematurely, especially in 2019-2020 models. May be related to EyeSight system or other electronic systems drawing excessive parasitic current.

EyeSight system turning itself off unexpectedly. Sensors may require cleaning or recalibration. Windshield replacement can affect system operation.

Auto start-stop function behaving erratically, not engaging when it should or engaging when unwanted. Software updates may address issue.

TCV regulates cabin and engine temperature. Failure can cause vehicle to go into safe mode, limiting power. More common in early model years.

Coolant bypass valve failures particularly in 2019-2021 models. Subaru issued service bulletin in February 2022 for replacement despite no formal recall. Can cause overheating or engine temperature regulation issues.

The sixth generation Forester launched in 2025 and is too new to have established long-term reliability patterns. The redesigned Subaru Global Platform offers 10% stiffer torsional rigidity. Hybrid model introduces new potential issues related to hybrid battery and electric motor systems.

While redesigned with improved transmission cooler and 3,500 lb towing capacity (Wilderness trim), CVT reliability should be monitored given previous generation issues. Lineartronic CVT is revised but based on similar technology.

New hybrid model adds complexity with electric motor, hybrid battery, and regenerative braking systems. Long-term reliability of hybrid components unknown. Requires specialized maintenance and diagnostics.