Abstract: A filter head of an engine includes a conduit extending along a longitudinal axis and a thermostat extending longitudinally within the conduit. The thermostat is movable between an open position and a closed position. The filter head also includes a sealing member positioned within the conduit downstream from the thermostat. The thermostat abuts the sealing member to inhibit flow through the conduit when in the open position and the thermostat is longitudinally spaced apart from the sealing member to permit axial flow of fluid through the conduit when in the closed position.