Mazda 3 2018 Owner's Manual page 521

If Trouble Arises
Overheating
If you find a leak or other damage, or if
coolant is still leaking:
Stop the engine and call an Authorized
Mazda Dealer.
Cooling system cap
Coolant reservoir
Cooling fan
If you find no problems, the engine is
cool, and no leaks are obvious:
Carefully add coolant as required (page
6-25).
CAUTION
If the engine continues to overheat or
frequently overheats, have the cooling
system inspected. The engine could be
seriously damaged unless repairs are
made. Consult an Authorized Mazda
Dealer.
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Mazda3_8GE4-EA-17F_Edition1 2017-4-7 11:59:21