The parts stores do not seem to be able to find in their computer files what I think is a temp switch on the head -- definatly threads into the water jacket--between cly 3 / 5 above the exhaust manifold. Can anyone here help me out with the proper terminology or part number?
Thanks in advance Bob

 

What your looking at is the Knock Sensor. Orielly #2KS28

 

Your temp switch, or coolent temp sending unit should be located right under and left of your thermostat.

 

its a coolent temp sensor on the passenger side of block

 

there's a technical difference when asking for parts,

Coolant temp switch would either turn on elec fan or warning light

Temp "sensors" will provide scaled info to the ECM and Gauge

not sure but i think the one at the thermostat outlet is typically for the ECM(could be 2 - 1 for ECM 1 for Gauge),

the one on the head could be a switch for the light ( used to be that way on older GM's)

knock sensors are under the head, screwed into a blocked hole in the side of the block usually opposite of the starter (LH/Drivers Side) where the middle crank bearing boss is, some engines may have 2

hope this helps,

I need to get my gauge working too

 

It is the coolant sensor for the temp gage/light.