What is the sensor on the side of the block between the number one and number three plugs?

1994 CHEVROLET SILVERADO
255,000 MILES • 5.7L • V8 • 2WD • AUTOMATIC
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CARLOS ORTEGA
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  • 8 POSTS
I would like to know what the sensor on the side of the block between the #1 and #3 spark plugs is called. I thought it was the temperature sensor and then I watched a video and they called it the "coolant temperature sending unit" which makes no sense if the temperature sensor unit is on top of the block in front of the thermostat which I replaced. My temperature gauge only goes up to about 150 or 160 which can't be right is why I am wondering about this. I will do more research but any help would be appreciated. Thanks.
Jan 4, 2021 at 4:58 PM
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DANNY L
  • ✓ASE Certified Mechanic
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Hello again, Danny here.

That auxiliary cooling fan temperature sensor located in the cylinder head is used in conjunction with the coolant temperature sensor located next to the thermostat. The auxiliary temperature sensor is used to control an auxiliary electric fan if equipped. I've attached pictures below showing its location and description. Hope this helps and thanks again for using 2CarPros.
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Jan 4, 2021 at 10:01 PM
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CARLOS ORTEGA
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Okay! Got it it. I found the answer here, disregard my last message.
Jan 5, 2021 at 7:53 AM
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DANNY L
  • ✓ASE Certified Mechanic
  • 5,648 POSTS
  • ASE Certified Mechanic
You're welcome!
Thanks again for using 2CarPros and we hope you will use our site again in the future.

Danny-
Jan 6, 2021 at 4:11 PM
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JESSEWA
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location shown is on passenger side of 7.4l, not a 5.7l between the #1 and #3 plug on driver's side.
Sep 16, 2022 at 5:26 PM
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