Author Topic: Mechanical Temp sensor and guage???  (Read 1265 times)

Offline JohnnyPopper

  • Senior Member
  • ****
  • Posts: 2562
  • Old Goof
Mechanical Temp sensor and guage???
« on: October 21, 2021, 08:02:19 PM »
Getting ready to drop the motor in the "80 C10, looks like the sensor had a coil coming from the part that looks like a thermocoupler.

It's about 3/8 diameter screwed into a larger brass fitting that matches the head opening

The gauge has the same type of coiled wire.

Was this stock? In calling/looking for a replacement all I see are electric sensors.  ???

Brain trust! Where are you???
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6465
Re: Mechanical Temp sensor and guage???
« Reply #1 on: October 21, 2021, 08:22:05 PM »
Someone swapped in a mechanical gauge.  The original was electric.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline JohnnyPopper

  • Senior Member
  • ****
  • Posts: 2562
  • Old Goof
Re: Mechanical Temp sensor and guage???
« Reply #2 on: October 22, 2021, 02:24:44 AM »
Wow, why would they do that???

Thanks bd, any info on where/when they used mechanical? Just curious?

Were they cheaper? More of a PIA in my opinion.... ::)
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6465
Re: Mechanical Temp sensor and guage???
« Reply #3 on: October 22, 2021, 10:39:20 AM »
Regarding light-duty GM trucks, OEM pre-1978 oil pressure gauges were mechanical; all the remaining factory installed gauges (save for the speedometer) were electric from 1967 forward.

Old school thinking, perhaps.  Generally, good quality mechanical gauges are a little more accurate than the factory installed electric gauges with greater scale detail.  Someone may have experienced cooling issues and didn't trust the OEM gauge.  Or, maybe they were enticed by some "cool" or "high performance" factor, because of the greater detail in the temperature indication.  The factory electric gauges are accurate to ħ ~7%, so the swap wouldn't have been grossly beneficial.

Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline JohnnyPopper

  • Senior Member
  • ****
  • Posts: 2562
  • Old Goof
Re: Mechanical Temp sensor and guage???
« Reply #4 on: October 22, 2021, 01:05:21 PM »
You solved the mystery bd! It's hooked up to an aftermarket gauge that has a greater scale.

Wow, all that work for what?  ::)

Can't wait to throw it away... 8)
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19038
Re: Mechanical Temp sensor and guage???
« Reply #5 on: October 22, 2021, 07:44:28 PM »
People are dumb and do lots of dumb things, especially to vehicles. These trucks were a prime target for it all. Basically, open a JC Whitney catalog from 1989, and here we have it.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline JohnnyPopper

  • Senior Member
  • ****
  • Posts: 2562
  • Old Goof
Re: Mechanical Temp sensor and guage???
« Reply #6 on: October 22, 2021, 10:19:43 PM »
Understood- "if you find a holy cow, milk it for all it's worth"
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction