Used Subaru engines are available through salvage yards, Japanese import engine suppliers, and online auto parts dealers. Common engines include the EJ25 2.5L four-cylinder, the EJ20 used in older Impreza and Legacy models, and the FA20 found in the BRZ and newer Forester variants. Subaru's horizontally opposed boxer engine layout requires careful inspection for head gasket condition, which is a known concern on EJ-series engines. Japanese domestic market imported engines are popular due to lower mileage. Always verify compression levels, check for oil leaks around the cylinder heads, and confirm the engine's compatibility with your vehicle's transmission and electronic control systems.