The Mazda RX 7 is known for its unique engine. Mazda's rotary engine operates differently from the typical automobile engine. But it still generates heat and must be liquid-cooled like the vast majority of automobile engines. Coolant is stored in the radiator. Its flow through the engine for cooling is regulated by the engine's thermostat. The Mazda RX 7's thermostat functions just as a any other car's thermostat does, and the replacement procedure is also similar.
Position a drain pan below the radiator and open the drain valve. Drain the radiator until the coolant level is below the thermostat. This should take about one gallon of coolant.
Unscrew the hose clamp connecting the radiator hose to the thermostat housing, with a socket and ratchet or screwdriver. Then remove the hose from the thermostat housing.
Disconnect the electrical connector from the coolant temperature sensor, if applicable.
Unscrew the thermostat housing's nuts and bolts, then remove the thermostat housing and gasket. Then pull out the thermostat.
Reconnect the electrical connector from the coolant temperature sensor, if applicable.
Clean all the surfaces that will contact the new gasket.
Install the thermostat into the cylinder head or manifold, with the temperature sensing pellet toward the engine block.
Install a new mounting gasket and place the thermostat in its position.
Secure the thermostat housing with its mounting bolts, and torque them to 14 to 22 foot-pounds.
