2005 Honda Civic Owner's Manual - Page 197

If the Engine Overheats 7. If there was no coolant in the reserve tank, you may need to add coolant to the radiator. Let the engine cool down until the pointer reaches the middle of the temperature gauge or lower before checking the radiator. 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. 9. Start the engine, and set the temperature control dial to maximum heat. 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 watch the temperature gauge. If it goes back to the red mark, the engine needs repair (see Emergency Towing on page 209 ). 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. Taking Care of the Unexpected 199