My friends Chevy Cobalt popped a coolant hose out of the clip?

The one from reservoir to engine. What would cause this? Closed thermostat? Radiator cap? A few months ago, I replaced the black plastic piece the ho

The one from reservoir to engine. What would cause this? Closed thermostat? Radiator cap? A few months ago, I replaced the black plastic piece the hose plugs into. It had a crack and leaked. It has sensors in it. Opposite side from the water pump

or:The one from reservoir to engine. What would cause this? Closed thermostat? Radiator cap? A few months ago, I replaced the black plastic piece the hose plugs into. It had a crack and leaked. It has sensors in it. Opposite side from the water pump

Tags:engine,closed,