"low coolant" light problem

[95riosnake]

Lately when my car has sat for a while (like 8 hours or more), the "low coolant" light will come on when I start the car and will stay on till the car is shut off. I'll drive the car 10 minutes to where I am going, then 5 minutes later when I go to leave, I'll start the car up and there will be no "low coolant" light...

What could be causing this? The temp gauge isn't above normal operating temp, and the radiator overflow shows my coolant at the right level...

Any help is appreciated

 

[StL3GTJLH]

what about your actual radiator, is it full? I was having a similar problem and it ended up being the bypass hose and one other hose right next to it were leaking, i replaced them and now no problems!

 

[95riosnake]

I'll give that a try...thanks

 

[HISSIN50]

if the level is alright, pull the sensor out of the overflow bottle and clean it. most of them that have never been cleaned are filthy.

good luck.

 

[MadHandle8169]

Are you supposed to fill the reservoir completely up because there is a black magic marker line drawn in the middle of mine.

 

[mo_dingo]

Are you supposed to fill the reservoir completely up because there is a black magic marker line drawn in the middle of mine.

No, it's not supposed to be 100% full. There are two lines on the bottle (raised lines on the plastic. One is warm, one is cold.

I would try this. Remove the overflow bottle cap and pull the sensor out of the bottle. Clean the connectors and take a piece of bare wire and short out the two tabs. The coolant light should turn off if you start the car. If it doesn't, you have a wiring problem at the sensor. All it does is run current into one wire, and if the water is there, it will pass the current through the other tab. Nothing fancy.
Scott

 

[urban96]

No, it's not supposed to be 100% full. There are two lines on the bottle (raised lines on the plastic. One is warm, one is cold.

I would try this. Remove the overflow bottle cap and pull the sensor out of the bottle. Clean the connectors and take a piece of bare wire and short out the two tabs. The coolant light should turn off if you start the car. If it doesn't, you have a wiring problem at the sensor. All it does is run current into one wire, and if the water is there, it will pass the current through the other tab. Nothing fancy.
Scott

i had the same problems, cleaned the little metal prong looking things and no more problem

 

[95riosnake]

No, it's not supposed to be 100% full. There are two lines on the bottle (raised lines on the plastic. One is warm, one is cold.

I would try this. Remove the overflow bottle cap and pull the sensor out of the bottle. Clean the connectors and take a piece of bare wire and short out the two tabs. The coolant light should turn off if you start the car. If it doesn't, you have a wiring problem at the sensor. All it does is run current into one wire, and if the water is there, it will pass the current through the other tab. Nothing fancy.
Scott

Cool, I'll give that a shot once it stops raining outside so I can pop the hood lol. I can't wait to go home and have a garage again!

 

[95riosnake]

did it today and worked like a charm! thanks guys

 

[94Silverbullet]

when this happened to mine, all I did was added antifreeze to the cold line before I started the car and the problem went away.

 

[tderrick]

This seemed to happen to all of us at about the same time. After 10 years or so, the contacts on the sensor just got corroded.

 

[95riosnake]

This seemed to happen to all of us at about the same time. After 10 years or so, the contacts on the sensor just got corroded.

yea, there was a bunch of black nasty sh** all over the contacts