WTF is spark knock and do I have this problem?

 

It's when the A/F mix in the cylinder ignites before the plug supplies the spark. Causes a pinging sound.

Hard to diagnose the condition based on your explicit details.

 

To be a little more specific, ping and spark knock is the fast rise in cylinder pressure to near top dead center when the piston and rod are nearly in alignment vertically and cannot move in response to the pressure.
The pressure peak has to occurr somewhere close to 12 to 20° after top center where the rod angle is able to push on the crank.
Any where much before this and the pressure spike "rings' the piston, rod, crank and block. This is what you hear as ping or spark knock.
Some of the reasons are fuel octane to low, timing to advanced, combustion chamber deposits, EGR incorrect operation, lean air/fuel ratios, overheating and blocked exhaust.