removing air from coolant

[VidaliA]

When my engine started overheating my first thought was to rev the engine as described in my manual to remove any air that may be trapped in the coolant. I just noticed on a diagram of my engine a little thing labeled "coolant air bleed", this may sound silly, but does this have to be open in order for the revving to remove and trapped air?

[Oswego John]

VidaliA,

See reply under "Trapped Air"

O J