Parts for your 2018 Subaru Legacy-Head gasket

2018 Subaru Legacy head gasket — what it does and how to look after it

Yes, the 2018 Subaru Legacy uses a head gasket. This is documented in the Subaru Factory Service Manual for the 2018 Legacy/Outback (FB25 and EZ36 engine sections), which details the multi‑layer steel (MLS) cylinder head gasket and the torque‑angle procedure for the head bolts. The official Subaru parts catalogue for the 2018 Legacy also lists cylinder head gaskets for both the 2.5‑litre FB25 and 3.6‑litre EZ36 engines. Independent workshop references such as the Haynes Subaru Legacy/Outback 2010–2019 manual cover the same component and service steps.

On a 2018 Legacy, the head gasket sits between the engine block and each cylinder head (it’s a flat‑four or flat‑six, so there are two). Its job is to keep combustion pressure sealed while also keeping engine oil and coolant in their own passages. An MLS gasket is used for durability and heat cycling, especially important in Subaru’s boxer layout where each bank runs horizontally under the bonnet.

This gasket isn’t a routine service item