Parts for your 2010 Subaru Impreza-Head gasket

2010 Subaru Impreza head gasket — purpose, service tips, and when to replace

Technical sources confirm a head gasket is absolutely used on the 2010 Subaru Impreza. The Subaru Factory Service Manual for the 2010 Impreza (engine/cylinder head section), the Subaru FAST parts catalogue, and general service texts such as the Haynes manual for late-2000s Impreza all specify a head gasket fitted between the EJ-series flat-four engine block and each cylinder head.

On the 2010 Impreza (2.0 and 2.5‑litre EJ engines, including turbo variants), the head gasket’s job is to seal high-compression combustion in each cylinder while keeping the engine’s oil and coolant circuits separate. It’s a precision multi-layer steel gasket clamped by torque-and-angle tightened head bolts. Because Subaru’s boxer engines have two heads and see plenty of thermal cycling, correct torque sequence and cooling-system care are vital to long life.

While a head gasket isn’t a routine “wear item”, looking after the cooling system hugely reduces the risk of trouble. Stick with the correct Subaru long-life coolant, mix ratio and bleeding procedure noted in the workshop manual. Many EJ engines also specify Subaru coolant conditioner via service bulletins