I was driving my 88 Corvette and the low coolant light came on. I checked the radiator for antifreeze and it appears to be normal and topped off. Just wondering what is causing this to happen.

 

Need more info. What was the coolant temp reading? How long have you been driving? ANY visible puddles on the driveway?

Weeding out the obvious. Mine actually had two issues that gave off the low-coolant light.

1. I didn't 'burp' the cooling system correctly when changing coolant.
2. My low-level sensor wire had a short.

I'm guessing yours was probably number 1.

 

If you get the light on when running the engine with radiator cap off and coolant visible to over the sensor then the problem is in the sensor or wiring.
If the light only comes on when the radiator is "buttoned up" I would say it's due to air in the system.

 

As mentioned, "burp" issues are the most common cause of your issue.

If you are unfamiliar with the proper burp procedure, I believe it is in the C4 tech notes.

I also had the intermittant "low coolant" light, and the burp procedure fixed it for me.

 

1. Fill the overflow tank to the cold full mark. Start the car and let it idle. Periodically squeeze the upper radiator hose with a rag around your hand. Once the hose is no longer hard, the stat has began to open and coolant is now circulating.
Have someone raise the engine rpm to about 2200 and hold it there. The coolant level in the radiator will drop. Remove radiator cap and fill with coolant all the way to the top with rpm's raised. Replace radiator cap before letting the rpms back down.
Drive the car normally. Repeat this once a day for the next several days, until you can't add anymore coolant.

2. I fill the radiator and part of the overflow tank...start the car with the cap off....when the car heats up and t-stat opens, you'll see the coolant level drop...when it does that, raise the idle to 1500+ and add additional coolant and put the cap on tight.....before the system becomes fully pressurized, raise the idle and remove the cap, add additional coolant and "button it up"......never had a problem with this procedure...other procedures will work just as well....

3. Drill two holes either 3/32 or 1/8 inch in diameter into the body of the thermostat. then all you need to do is check the level, it burps itself. Here is a thermostat photo to illustrate how to drill the holes.

 

Have the same problem with my 97 Z-28 turns out the sensor is bad. I just keep an eye on coolant level and also temp gauge. No issues as of this time and have had this problem for quite a while.

 

I had that problem. 1st clean connector on sensor with sand paper. Just drove mine 250 miles and not even a flicker. Was on every time I drove before.

 

Before you go drilling holes in your thermostat maybe you should read this:


http://forums.corvetteforum.com/show...16&forum_id=48

 

The purpose of the holes is to let the trapped air out from under a closed thermostat thereby allowing you to purge the unwanted air out of the cooling system.

 

With all due respect for central coasters post, this time he's 100 % wrong. A small hole or two won't change how the thermostat functions. It just lets the trapped air out of the block.