How do you replace the thermostat on a 2002 Mazda Protege?
Remove the negative battery cable, remove rad filler cap and find the lower rad hose. Get a container as when you remove the hose from the engine side, you will lose 3-4 litres of coolant. You may want to remove the air intake box that runs on top of the rad (2 10mm bolts) first. Once hose is off the thermostat is behind the cover the hose was connected to..remove the 2 12mm bolts and replace unit with a new seal. Reverse process, add new coolant and follow procedures to ensure no air lock in coolant system occurs.
The thermostat is located on the front left of the engine housed in the lower radiator hose that attaches to the engine. You remove the thermostat cover which exposes the thermostat gasket and thermostat. You must disconnect the negative battery cable. Remove the fresh air duct, remove the air cleaner, drain the engine coolant before removing the thermostat cover.