It sounds like the thermostat is not working or somthing along them lines. That was the sound of boiling water. Fix that before going any further, do not over heat the thing or you may need a head. If you don't have a fan shroud get one. Use a Montero one. There metal and easy to find at the recycle places. Any fan more then 2 inches away from a radiator must have a shroud. Not enough air to cool it at idle. This is just one of many Mitsubishi's mistakes.