Parts for your 2002 Subaru Legacy-Head gasket

2002 Subaru Legacy head gasket: what it does and how to look after it

Referencing the Subaru Factory Service Manual for the 2002 Legacy/Outback (Engine section) and Subaru Technical Service Bulletin 09-36-03 and later updates on external coolant seepage, plus the Subaru OEM parts catalogue for EJ251/EJ252/EJ253 and EZ30 engines, it’s clear the 2002 Subaru Legacy is fitted with cylinder head gaskets. As a boxer (flat) engine, it actually uses two—one per cylinder head—so the head gasket is absolutely relevant on this model.

The head gasket’s job is to seal combustion pressure while keeping engine oil and coolant in their own passages. On the 2002 Legacy’s flat-four and flat-six options, a healthy gasket means stable temps, clean oil, proper heater performance, and full engine punch. When it starts to give up, owners may notice a sweet coolant smell, a damp line at the head-to-block seam, bubbles in the overflow, fluctuating temps, or milky contamination.

Servicing-wise, there isn’t a set replacement interval—condition and cooling-system care are everything. Keeping the radiator, cap, thermostat, and hoses in top nick, and running the correct Subaru coolant mix is essential. For affected Phase II 2.5-litre engines, Subaru’s TSB recommends adding the Genuine Cooling System Conditioner