Kinda weird temperature readings

Heating / Cooling / AC

  1. Princess Valiant

    Princess Valiant Duster specialist

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    So I have a daily driven 68 dart with a 225 slant six. For as long as a can remember, normal temp is the gauge reads just above half way in the sweep in the middle of the normal range. The other day on Monday I took the radiator cap off to check the level because i was going to go on a trip (120 miles away)

    The level was ok so I didn't add any. Since then the gauge is reading at the very low end of the normal range, almost into the cold side.

    Even after driving the 120 miles and back, it's reading on the low end. Almost a week later and it's still reading on the low end from a dead cold, no matter what i do or how hot it is outside.

    BTW: NON a/c car and runs and drives fine with no other known problems.
     
  2. RustyRatRod

    RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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    Use an infra red temp gun at it and see what it says. Sounds like the sending unit may be bad.
     
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    • Tooljunkie

      Tooljunkie King of cobble/master of the broken bolt FABO Gold Member

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      Or high resistance at connector (dirty)
       
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      • Alaskan_TA

        Alaskan_TA Well-Known Member

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        Make sure the cap is seated all the way.

        If it is, check the seal to see if it tore.
         
      • moparmat2000

        moparmat2000 FABO Gold Member FABO Gold Member

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        Or you may possibly have a thermostat thats stuck open. Had that happen to me. You may want to mount a good aftermarket temp gage under the dash that has actual numbers on it.
         
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        • brian6pac

          brian6pac Well-Known Member

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          Just squeeze the upper rad hose when it's hot, if you can collapse it it's not holding pressure and if you can hold your hand on it then it's probably under 140*F
           
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          • Mike69cuda

            Mike69cuda 66 is the new 17 FABO Gold Member

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            The infrared temp guns are $15 on Amazon & work great. You can even use them for human thermometers.
             
          • Dartnut

            Dartnut Don't hate me because i'm beautiful

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            I hate to tell you this, but your car is at the end of it's service life.
            It's time to take it to the scrap yard and buy a new Toyota.
            This is the only sensible solution to your problem.

            Or you can follow the advice already given (which is excellent), fix it for under 20 bucks, and keep it on the road for another 51 years.
             
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            • moparmat2000

              moparmat2000 FABO Gold Member FABO Gold Member

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              Go with option #2 keep it on the road another 51 years
               
            • Syleng1

              Syleng1 Karma is real and Life is short... FABO Gold Member

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              Thermostat is the answer- stuck open.
              Stuck open and the radiator is cooling faster than the engine can produce heat.
               
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              • Dartnut

                Dartnut Don't hate me because i'm beautiful

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                Agreed 100%.
                I was just trying to pull her leg..........lol
                 
              • 67Dart273

                67Dart273 FABO Gold Member FABO Gold Member

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                Just turn the radio up a little louder..............
                 
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