HINT: Check the coolant level when the engine is cold.
1. CHECK ENGINE COOLANT LEVEL AT RADIATOR RESERVOIR
The engine coolant level should be between the "LOW" and "FULL" lines at normal temperature (20C(68F)).
If low, check for leaks and add "Toyota Super Long Life Coolant" or similar high quality ethylene glycol based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid organic acid technology up to the "FULL" line.
2. CHECK ENGINE COOLANT QUALITY
(a) Remove the radiator cap.
CAUTION: To avoid the danger of being burned, do not remove the radiator cap while the engine and radiator are still hot, as fluid and steam can be blown out under pressure.
(b) There should not be any excessive deposits of rust or scale around the radiator cap or radiator filler hole, and the coolant should be free from oil.
If excessively dirty, clean the coolant passages and replace the coolant.
(c) Reinstall the radiator cap.