Any leak or water loss on any engine should be treated with the upmost urgency. Modern engines are designed to work at high temperatures to aid combustion. Water boils at 212 degrees F or 100 degrees C. The cooling systems work at 89 degrees C and often in extreme conditions achieve over 100 degrees C in operation. The system is pressurised, each pound of pressure raises the boiling point of coolant by 2 degrees F. So providing there are no leaks allowing the pressure to bleed away, a 15 psi system should not boil until the coolant temp reaches 242 degrees F or 116 degrees C. So if you do not have the hoses pressurised at normal temp then you may have a problem. Any leak in the system bleeds away pressure that is working to prevent boiling and therefore does not allow the pressurised system to work for you. Flacid hoses at normal operating temperature are not a sign of a good engine but more a sign of a pressure leak. It is that pressure that keeps your engine safe. Guard against it's loss.
