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Discussion Starter #1
I have a '99 Sierra with the 4.3 in it. My low coolant light comes on about once a month. The coolant level never drops, I am not blowing white smoke out of the exaust, there are no leaks in the cooling system and the oil is not a milky white it is clean. The only thing that I can think that is wrong is I might have a bad sensor. Has anyone else had this problem before????
 

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I'll Take teh Case!
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I would think it is a bad sensor too...we had a similar problem with our '98 Trans Am. Low coolant light came on one day and stayed on until we replaced the sensor. Sensor was very $$$$, but we saved labor by installing it ourselves...simple job on the ls1...not sure about the 4.3 :think:
 

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internet bigot®
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if you have constantly checked the coolant level.. and it doesnt drop, next best bet would be sensor... are you checking the coolant when it is cold?... because when it is warm it expands...
 

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Mine used to do that,even with the water level above the min mark,I still had to put a little more coolant in to keep the light from turning on.
 

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it doesnt take much to turn that light on...mine came on, and gradually got worse. turned out the water pump was bad....only 45K on it. never even leaked on the ground, burned off on the engine, i could only see it by looking closely or feeling the bottom of the pump
 

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steveoh1 said:
it doesnt take much to turn that light on...mine came on, and gradually got worse. turned out the water pump was bad....only 45K on it. never even leaked on the ground, burned off on the engine, i could only see it by looking closely or feeling the bottom of the pump

Yup, my water pump went bad at about 72k, and the light stopped coming on after i changed it, but the past few weeks it comes on everyday, but my coolant is always good to go. oh well, damn 4.3L
 

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My 02 Chevy did the same thing at 4k and this what I was told to do unplug the sensor and clean the contacts blow out the dust in the plug no problem sence.
 

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i wish MY truck had a low coolant light. I left my house to make a 2 kilometer trip. half way there my temp is above 100 degrees. by the time i roll into the parking lot and park there is steam everywhere. turned out to be a broken heater core :(
 
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