quick question about sensors on back of cylinder head

[jonnaz]

3b engine there is the coolant temp sensor with the 2 pin white plug and another (what looks like a sensor, just has a metal button like shape as if somthing were suppose to push on to it) below it on the back of the head. what is it and is there suppose to be a wire going to it because on mine there is not.

cheers

[mcandmar]

S2 heads have a metal plug screwed in just below the sensor with a small allen key head in it. Cant remember if its an oil or coolant passage.

[Knight Rider S4]

No wire going to it ..picture of what rear of cylinder head looks like

[jonnaz]

thanks guys question answered. thanks for the pic.

[S2central.net]

that'll be a core plug !