Cooling System: Description and Operation

ENGINE COOLING
The cooling system components are the:
^ engine coolant temperature sensor (ECT sensor)
^ radiator
^ degas bottle
^ radiator draincock
^ water pump
^ water temperature indicator sender unit
^ water thermostat
^ dual speed fan motor assembly

The water pump circulates the coolant.
The water thermostat:
^ controls the engine coolant temperature.
^ allows quicker engine warm-up.
The degas bottle:
^ provides a location for fill.
^ contains coolant expansion and system pressurization.
^ provides air separation during operation.
^ replenishes the engine coolant to the system.
The fan motor:
^ operates only when the ignition switch is in the RUN position.
^ will not operate with the switch in the OFF position.
The engine coolant flows:
^ from the lower radiator hose to the water pump.
^ from the water pump to the engine block and the cylinder heads.

A closed water thermostat returns the engine coolant to the water pump; an open water thermostat allows the engine coolant to flow to the radiator.

Engine coolant provides freeze protection, boil protection, cooling efficiency and corrosion protection to the engine and cooling components. In order to obtain these protections, the engine coolant must be maintained at the correct concentration and fluid level in the degas bottle.

When adding engine coolant, use a 50/50 mixture of clean, drinkable water and engine coolant.

Caution:
^ The cooling system is filled with either green-colored or yellow-colored Mazda Premium Engine Coolant meeting Mazda Specifications. To determine the vehicle's coolant type (color), check the coolant reservoir.
To maintain the integrity of the coolant and the cooling system and maintain the warranty on the cooling system:
^ Add Mazda Premium Engine Coolant of the type of coolant originally equipped in the vehicle. If you are unsure which type of coolant the vehicle requires, check the coolant reservoir.
^ Do not add/mix an orange-colored, extended life coolant such as Mazda Specialty Orange Engine Coolant, meeting Mazda specifications with factory-filled coolant.Mixing Mazda Specialty Orange Engine Coolant or any orange-colored extended life product with the factory filled coolant can result in degraded corrosion protection.
^ A large amount of water without engine coolant may be added, in case of an emergency. In this instance, the cooling system must be drained and refilled with a 50/50 mixture of engine coolant and distilled water as soon as possible. Water alone (without engine coolant) can cause engine damage from corrosion, overheating or freezing.
^ Do not use alcohol, methanol or brine or any engine coolants mixed with alcohol or methanol antifreeze (coolant). Alcohol and other liquids can cause engine damage from overheating of freezing.
^ Do not add extra inhibitors of additives to the coolant. these can be harmful and compromise the corrosion protection of the engine coolant.
^ Do not mix with recycled coolant unless from a Mazda-approved recycling process. (See Use of Recycled Engine Coolant section of the owners manual.)