I don't see the bolt. That big plastic part with the "X" on top fails...or more likely its gasket fails.
The gasket from that plastic block to the head needs to be replaced. Possibly the entire plastic block as well if you don't trust it. If it were me and that plastic block wasn't too expensive I'd replace it. Heat is murder on plastic engine parts. I'd recommend new hoses too.
Here is a vid showing coolant shooting up like you are experiencing: