Originally Posted by
Mrmiata
Since you didn't go into detail.. You realize getting the engine hot to open the thermostat and then inducing cold water is not a good combination.. not to mention the thermostat will then close with the cooler temp from the water. So unless you intend to hook up to the home hot water tank..
Using cold water on an engine warmed to operating temperature is not a problem. You never want to add any water, hot or cold, to an engine that is overheated. It must cool down first before adding water.