Mazda6; 2.3L. MazdaSpeed6. Engine Coolant Thermostat Gasket. From 11/01/2006. From 11/27/2006. Thermostat Housing Gasket. To 11/01/2006. To 11/27/2006. seal. unit. W. Pump Inlet. Engine Coolant Housing. Water Neck. Included with: Thermostat unit, Water outlet.