Low coolant light
12-19-2007, 11:51 AM
#1
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Low coolant light Ok, my low coolant light has been off the whole time i have owned the car. A few times it would pop on for about 10-15 minutes, and then it would go off. Now that its getting colder, sometimes it turns on and stays on, and other times it turns on for a while and then goes off. It seems like after a few days of freezing temps (like teens to mid 20s and the light is off), once it hits over 30 degrees outside the light wants to come on and stay on. So my question is, do I actually have low coolant or is the weather just ******* with me? I have never touched anything coolant related, so I will ask the retarded question of the best and safest way to fix this?
12-19-2007, 12:25 PM
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You need to take a look in the radiator when it is stone cold. The coolant should be right to the neck. These low coolant sensors have a reputation for going bad. Some people just unplug them.
If the coolant is down you may have a bad cap that is allowing coolant to go into the overflow but not back again.
I have been pushing coolant out into the expansion tank on my 95 leaving the radiator a little low. It doesn't take much for the light to come on. I would fill the radiator with just a few cups of coolant and the light would go off. To shorten the story, I pulled my overflow tank, emptied and cleaned it. Filled it to the right level and the radiator now seems to be keeping itself full.
Worse case is a bad head gasket pressurizing the system and forcing the coolant out the overflow. When the engine cools the coolant shrinks to create a vacuum that draws the overflow back in - that works if the coolant level has not been depleted too much. That's how it's supposed to work anyway.
If the coolant is down you may have a bad cap that is allowing coolant to go into the overflow but not back again.
I have been pushing coolant out into the expansion tank on my 95 leaving the radiator a little low. It doesn't take much for the light to come on. I would fill the radiator with just a few cups of coolant and the light would go off. To shorten the story, I pulled my overflow tank, emptied and cleaned it. Filled it to the right level and the radiator now seems to be keeping itself full.
Worse case is a bad head gasket pressurizing the system and forcing the coolant out the overflow. When the engine cools the coolant shrinks to create a vacuum that draws the overflow back in - that works if the coolant level has not been depleted too much. That's how it's supposed to work anyway.
12-19-2007, 12:47 PM
#5
Yes you can open it,car doesn't take but a few hours to cool off. You should have the green stuff in your car,someone correct me if I'm wrong. Buy 50/50 mix of coolant if it is low, make sure it doesn't say dex-cool anywhere on it. I doubt its low, but check anyway, I'd bet money its just the sensor.
12-19-2007, 01:17 PM
#6
Mine did the same thing after I bought it but the coolant was always full. It was the sensor. I would put money down that it is your problem. The easiest thing to do is unplug the sensor wire harness, thats what I did. Of course you could replace the sensor. Check out this link for a good pic and explanation of the sensor.
http://shbox.com/1/low_coolant2.jpg
http://shbox.com/1/low_coolant2.jpg
12-19-2007, 02:34 PM
#7
GM has been using that same design of sensors for years. I used to replace them quite often on newer Impalas at the dealership that I used to work at. GM service claims that if the coolant becomes contaminated even the slightest that it hacks the sensor off and thus the light comes on. I'd say the sensor is likely your problem. Just un hook the stupid thing
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12-28-2007, 04:37 AM
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I didn't get any notifications for this thread so I couldn't respond to your questions. Assuming you have the green glycol antifreeze, as that's what came with your year of car - any of the same should be good. I don't see any antifreeze now that doesn't say that it can be mixed with the other type (red = Dexcool) but I want to keep them separate anyway. If you open your cap and see red, stay with Dexcool. If green, any green glycol (silica compound) antifreeze will work.
How did you make out?
How did you make out?
