Who in the world said you could run a car without a radiator cap? Water which makes up about half of your coolant mixture boils at 212 degrees. Coolant Temperatures inside your engine often exceed 212 degrees as it moves toward the radiator. Increased pressure raises the boiling point of any liquid. Your radiator cap allows 6-8 psi of pressure to build in the cooling system thus preventing boilover from too high temperatures. As the water in your cooling system is heating it is expanding. As for the gushing water, as long as the engine is running the water pump is applying pressure to the water in the block as it pushes against the thermostat. Shut down the water pump and the pressure goes to zero and all that water which is at 212 degrees or higher boils. Water expands at a rate of 1700 to one when it boils so when it boils inside the cooling system the remaining water has to go somewhere. As for the top hose collapsing, it's possible the coolant being pulled into the engine is pulling a vacume on the radiator that shows up in the top hose. You didn't mention whether the engine was overheating or not. I'd suggest trying a new radiator cap first.
|