Throughout this site we use many technical terms, and given the breadth of readership our site enjoys, sometimes we are remiss and incorrectly assume everyone knows what we are referring to. For those that do not, here are some explanations of the technical terms use.
Jiggle Pin
A mushroom-shaped pin inserted in a small hole in the plate valve of the thermostat in an engine's cooling system. The hole prevents an air lock building up when the valve is closed, which could prevent proper filling of the system. The jiggle pin effectively closes the hole when the flow from the pump causes a differential pressure across the closed valve.
