I have a 1990 GMC Sierra k1500, I've
recently been having fluctuating reading on
my coolant dashboard sensors going from
normal up to 260 and back down, it
constantly does this as I drive. I have
changed out both coolant temperate
sensors and my thermometer (I did not use
a torque wrench but don't see that being
the problem, though I may stand corrected)
I don't know what else to do to fix this
problem. I believe the engine it self if
staying at a normal temperature, I don't
know for sure, but I am puzzled by these
reading. Thank you for your help.
To see if the temperature is correct they sell a cap that will tell you what the temperature is you may what to try to make sure you temp is ok. https://store.schnitzracing.com/schnitz-high-pressure-temperature-gauge-radiator-cap/?gclid=CNyKyseV7coCFcFZhgod1JIOrQ
Ya but still need to check things out. Hard to say from back here, but to be safe, I would change out the thermostat and the temperature sending unit. Also make sure the cooling system is purged from air pockets when refilling.
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