What is this sensor?

[redneck_reed78]

This was in I believe the driver side head, the other side had a knock sensor in it about similar location if I remember correctly

You must be registered for see images attach

. This looks like a coolant temp sensor to me but the plug is not like anything I can find online. So is that what it is? I can't go look at the truck because the engine and heads are at a machine shop. Thanks
OH and the truck is a 87 350 TBI engine.

 

[F-64]

Pretty sure that is the coolant sensor for the gauge in your dash. I'm not sure why they changed the terminal on it.
The one for your year.
https://www.summitracing.com/parts/...ear/1987/make/chevrolet/model/r10?prefilter=1
older version
https://www.summitracing.com/parts/ado-g1852

someone will chime in to elaborate

 

[Octane]

My truck has one exactly like it.
Temp gauge sensor. 1977 k10 350cid

 

[78C10BigTen]

My 78 is the same temp sensor too.

 

[CorvairGeek]

If you look carefully at the corresponding connector on the wiring harness, many GMs could plug into both the button style connector (like shown) by plugging on to the sensor perpendicular (with the little half circle cut out in the connector), or plugging straight on to a spade style connector. I have theorized this was done to make them more universal, and to distinguish between gauge and warning light sending units, but that is just my anecdotal observation.

 

[redneck_reed78]

I think you're on to something @CorvairGeek and like the rest of you suggests it appears the sensor is an earlier style.
With no definitive answer, instead of causing more headaches I'm gonna stick with the old saying "If it ain't broke don't fix it"

 

[C10MixMaster]

You must be registered for see images attach

these are all temp sensors with different terminals. the second one is a nail head design found on earlier chevys . the knock sensor should be in the bottom of the block and much bigger.

 

[Joshua Keith]

This was in I believe the driver side head, the other side had a knock sensor in it about similar location if I remember correctly

You must be registered for see images attach

. This looks like a coolant temp sensor to me but the plug is not like anything I can find online. So is that what it is? I can't go look at the truck because the engine and heads are at a machine shop. Thanks
OH and the truck is a 87 350 TBI engine.

Does it work? I’ll buy that from ya if you don’t want it.

 

[WarlVlachine]

Temp sensor for sure, just like everyone said. Green wire if I remember correctly, the connector slides on sideways kind of. looks just like a normal female spade. I've only ever seen the one that came in my 86'.

 

[Charlie]

https://www.repairconnector.com/products/GM-Single-Wire-Coolant-Temperature-Sender-Connector.html