Coolant Low Light on??

[brots06]

Yesturday i was driving home and the coolant low light came on so when i got home and i checked the level and it was fine but today i added a little bit more just to be safe, and i dont see it leaking out anywhere. But the light didnt go off its still on, so im thinking its a bad sensor or something? Ive have it come on before but it was because it was leaking out the overflow tube due to a bad head gasket, $900 later i got that fixed and it worked fine for about 3 months. Now the lights on again, any ideas?

[xeroinfinity]

what engines that brots06?the quad 4? sounds like it could be a faulty sensor, that can be tested i beleive. sometimes the coolant leaks into the exhaust and burns off as steam. And sometimes it goes in the oil. if you see no green leaks anywhere its going into the motor. when i run my GA's hard they sometimes spue out coolant through the overflow, and once it starts running it acts like a syphon and pours more than it needed to out. But dont trust the sensor if you are haveing troubles, keep a close eye on the coolant level. BWT did you fill the resivour when the car was running, that helps fill it completly up.

[brots06]

I have a '99 grand am gt ho 3.4, on tuesday ill bring it in to have it checked, i hope its just a damn sensor because last time it cost me 900 bucks for a new head gasket...

[Ridenour]

Brots, sadly, I would have to tell you the number 1 culprit : Leaking lower intake manifold gasket. That would be my number 1 guess. It happens on about 75% of 3.4's. If there's no leaking marks under areas such as the throttle body, then check your oil. If it is milky white; you deffinately have a leaking LIM gasket.

[brots06]

ok, but i dont understand why the level of the coolant would be fine then? But i dont know much about cars. Im gonna go check the oil and let you know what i find. thanks

[brots06]

the oil seems to look fine so i dont know...

[Ridenour]

oh oops I thought you said you had to add some. If you check the coolant, and the coolant doesn't seem to be contaminated w/ oil; then it's most likely a bad sensor.

[xeroinfinity]

"faulty sensor, that can be tested i beleive"

[skibum1111]

The sensor stuck on my 95, the only way to replace it was to replace the tank. Not sure about 99-up tho... One way to check it is to drain some coolant out of the system so you can remove the tank, take it out and shake it you should hear the float going up and down.

[xeroinfinity]

when the engines cold the Low coolant may come on, then when it warms up it says its full.

[skibum1111]

If the low coolant light comes on when the engine is cold, then the coolant level is below the low mark and the light should be coming on. It will go off if the level isn't all that low as coolant does expand when it gets hot, thus the need for an expansion tank on newer cars and full marks on radiators that were below the top of the radiator on older cars.

[kenny1]

Originally Posted by brots06

Yesturday i was driving home and the coolant low light came on so when i got home and i checked the level and it was fine but today i added a little bit more just to be safe, and i dont see it leaking out anywhere. But the light didnt go off its still on, so im thinking its a bad sensor or something? Ive have it come on before but it was because it was leaking out the overflow tube due to a bad head gasket, $900 later i got that fixed and it worked fine for about 3 months. Now the lights on again, any ideas?

ok same thing happened to me and i added coolant to the full line but light was still on so i overfilled it and that has solved the problem.

[brots06]

just to let you guys know i took it in today and it needed a new sensor which cost $12 and then i got charged $50 for labor!