3.5 LITER W/TURBO. Adapter bolt. A threaded rod with a drive head (such as hex, 12 point, torx, etc) on one end used to secure the Engine Coolant Outlet Housing or related components. Engine Oil Filter Adapter Bolt. HEX. HEAD. mount. Connector pipe. Engine Coolant Outlet Housing. Engine Oil Filter. Thermostat outlt. Water outlet.