2010 Honda Insight Owner's Manual - Page 403

If the Engine Overheats 9. Start the engine, and set the temperature to maximum heat (climate control to AUTO at '' ''). Add coolant to the radiator up to the base of the filler neck. If you do not have the proper coolant mixture available, you can add plain water. Remember to have the cooling system drained and refilled with the proper mixture as soon as you can. 10.Put the radiator cap back on tightly. Run the engine, and check the high temperature indicator. If it begins to blink or comes on again, the engine needs repair (see Emergency Towing on page 412 ). 11.If the temperature stays normal, check the coolant level in the radiator reserve tank. If it has gone down, add coolant to the MAX mark. Put the cap back on tightly. Removing the radiator cap while the engine is hot can cause the coolant to spray out, seriously scalding you. Always let the engine and radiator cool down before removing the radiator cap. 8. Using gloves or a large heavy cloth, turn the radiator cap counterclockwise, without pushing down, to the first stop. After the pressure releases, push down on the cap, and turn it until it comes off. 400 2010 Insight