FA24

Forum reports note audible timing chain noise against guides on FA24 engines, described as a grinding or rattling sound. While Subaru designates the timing chain a lifetime component, community and forum evidence shows it can develop noise and wear issues, particularly on neglected or aggressively tuned examples. A stripped timing chain causing jumped timing has been documented.

Community reports of oil weeping into spark plug tubes after valve cover gasket deterioration. This is a known maintenance item flagged by multiple owners. On the FA24, access requires removal of additional components, making it more labour-intensive than on simpler engines.

NHTSA complaints document EyeSight forward collision avoidance system triggering hard braking at highway speeds when no real hazard exists, creating rear-end collision risk. This is a software and sensor calibration issue rather than a mechanical powertrain fault.

Forum evidence notes that aggressive timing in ECU tunes on the FA24 can generate excessive cylinder pressure, leading to head gasket lifting. This is particularly relevant for owners who have modified or tuned their vehicles beyond stock parameters. Tuners with high timing advance are specifically implicated.

NHTSA complaint documents front brake pads worn to 1-2mm at only 23,520 miles on a 2022 model. The dealer declined to cover this under warranty. Given the WRX's performance nature and weight, front pads may wear faster than typical expectations, particularly in urban or spirited driving.

NHTSA complaint notes side mirror plastic components melting or deforming under heat and sunlight exposure, affecting visibility and aesthetics. Likely affects other exterior plastic trim components using the same material.