If this is allowed, so the performance was not up to the radiator and caused the engine temperature will rise or heat. As a result, your car will strike on the way. By filling water indiscriminate collection of rust will make the hose that connects the radiator to the engine. So the engine temperature will rise due to clogged pile of rust.
We recommend to fill the radiator with mineral water or distilled water. Can also use used water cooling or air-conditioning room in the house. Because water is more pure AC, and can be used on radiators.
Special for car owners who live on the outskirts of the sea or the housing estates that springs containing rust, Iwan also warned not to use the water that comes from that place. To avoid a pile of rust on the radiator and the radiator was able to work with the maximum.