Hi, I am not new here just had to re-register because I can't remember my old password. I'm was registered as Ironskull and I have a new ISP and email address so I can't recover the password. Anyway: I have a 1997 Z/28. I replaced the water pump and thermostat 2 years ago and everything has been fine. On the 4th of July I drove it and the low coolant light came on. I checked the level in the tank and it was just a bit low but not bad so I did add some dexcool. The light is still on and I keep checking and everything is full. The temp is keeping nice and cool also. What could be causing the light to be on even though everything is full? Thanks.

Jack

 

unplug it. It's on the top of your radiator on the passenger side

it does not talk to the computer


the manual as well as visual inspection device will continue to function normally for as long as you own the vehicle

 

Checking the level in the reservoir (pardon my French) doesn't necessarily guarantee that the radiator isn't low, which is where the sensor is. Something could be funky with the overflow/return function to where coolant isn't getting sucked back into the radiator as it should be.

 

I know that. I check the radiator. That is full too. The engine stays cool on the gauge too. That's why I am asking. Everything is full but the light is on.

 

Then the sensor, or wiring is bad. You can fix it if it bothers you, or monitor the coolant level the old fashioned way. Personally, I prefer checking things visually anyway, instead of waiting for an idiot light to go on, as that gives you a chance to check other things under the hood, like.....the oil. Phew! That sure is hard work popping off that radiator cap to make sure all is fine, isn't it?

 

I replaced my water pump and the next day the low coolant light came on. It was low even though I bled it. It would come on and off randomly thereafter for about another week, then I guess the air that was left naturally bled from the system. The light has not come on since. I think that just the smallest air bubble going past that thing sets it off. I was ready to just unplug mine, but decided to give it another chance. Just keep checking the level for the next week or so. It has to be to the top of the radiator fill neck.

 

I check everything once a week anyway. I just like the car to work right. I grew up in my dad's gas station (full service Standard Oil) in the 60's and 70's. I'm used to working on cars but the newer ones with all the electronics are a pain. My 92 Chevy full size truck and my 65 Chevelle are dreams to work on. OK, so the sensors just go bad sometimes. I should have figured. I'll replace it. I honestly don't mind checking things or working on them.

 

Radiator level is top of the fill neck. Shoot, would it have an air bubble from me changing the water pump from 2 years ago? I did bleed the system then and never had the light come on till July 4th of this year. Thanks for the answers. I will watch it for another week and then if it is still on I will replace the sensor.

 

Sorry, i misread and thought you just changed the water pump. my bad. Those sensors are expensive though, I think that's why most people just unplug it.

 

It's about a $35-40 part. My eyes work for free.