I heard a loud burst/pop sound, all coolant spilled out underneath?

Hello,

This sounds like the engine blew a head gasket and filled the cooling system with pressure which in turn popped a radiator hose. This also can be why the engine does not crank over because one of the cylinders is filled with coolant and won't compress. To confirm this issue, we can remove the spark plugs and then while standing back crank the engine over, if coolant shoots out from one or more of the spark plug holes the head gasket is blown.

Here are guides and how to remove the spark plugs so you can run the test:

https://www.2carpros.com/articles/head-gasket-blown-test

This guide can show you how to remove the spark plugs with images below to show you how on your car:

https://www.2carpros.com/articles/how-to-change-spark-plugs

Caution: Take great care when fitting spark plugs not to cross-thread plug, otherwise costly damage to cylinder heads will result. It is essential that only the correct grade of spark plugs approved for this engine are fitted. Incorrect grade of spark plugs may lead to piston overheating and engine failure.

Spark Plugs

Before disconnecting the battery, ensure all text and cautions in the battery disconnection procedure are observed.

Remove

1. Disconnect battery earth lead.
2. Remove ignition coils.
3. Clean area around spark plugs.
4. Remove 8 spark plugs.

Refit

1. Fit 8 spark plugs and tighten to 31 N.m (23 lbf.ft).
2. Fit 8 ignition coils.
3. Connect battery earth lead.

Please let me know what happens, Ken