Point of view of this article: According to subject, it must be that heat dissipation system is blocked or cylinder head gasket water passage is being purged.
First of all, water channel engine cooling system is a closed circulation system, which is driven by operation of water pump. The main function is to absorb heat generated by antifreeze when engine is running, enter water tank through circulation, and then dissipate heat by water tank and cooling fan, and then recycle cooled antifreeze to engine for next cycle. absorption and removal of heat. Therefore, if there is a blockage inside circulation system, heat of antifreeze cannot be removed, which will cause phenomenon of boiling water.
Secondly, there is another situation when, after water channel of engine cylinder head gasket is exposed, exhaust gases of high temperature and high pressure in combustion chamber will flow from damaged place into heat removal circulation system, which causes a sharp increase in temperature and pressure inside system, so these gases with high temperature and high pressure will be released when lid of water tank is opened, causing water to splash out of the pot.
I hope my answer helps you.
The above is just my personal opinion, feel free to comment/subscribe/like/.