Your Mazda Protege's thermostat sits between the engine and the radiator. It starts up in a closed position. It will block the flow of the coolant to the radiator until the engine has warmed up. The thermostat helps let your engine warm up as quickly as possible, which helps reduce engine wear, deposits and emissions.
FITS: 1995/1996/1997/1998/1999/2000/2001/2002/2003 Mazda Protege
2002/2003 Mazda Protege 5
Part #: BP6F-15-171A