[Fot] Radiator burping

[Randall]

IMO, burping a little after a hard run and sudden shutdown is normal.  There
is still a lot of heat stored in the cylinder head & block, but the water is
no longer circulating to carry the heat away.  So the residual heat causes a
little boiling in the head.

The real question IMO is why it didn't go into the overflow.  Sounds like it
may be blocked; or perhaps the upper lip of your radiator neck is damaged so
it doesn't seal to the cap.

Randall