2002 Limited with Low Coolant Light

[dudenamedric]

I just bought a 2002 Century Limited. The thing drives beautifully. I can't believe it's an 11 year old car. Anyways, I started the car and began driving home this afternoon and noticed that the low coolant light was not turning off. It wasn't constant, but flashing as I drove. I got home, popped the hood and checked out the coolant level in the overflow. I noticed that there's a cold and hot level toward the bottom of the tank, but the level of coolant was far higher than either of those lines, almost filled to the top. Do I have too much coolant in the overflow? Would that cause the light to flash? Does the light flashing indicate a problem or would it have to be constant to alert an issue with the coolant level? Any advice or information would be greatly appreciated.

 

[2000 Buick]

The low coolant level sensor is mounted on the passenger side of the radiator, about midway. It looks like a square box, about 1/2" in depth. If the coolant drops below this level, the sensor trips the light in the dash.

You need to pop the radiator cap off, when it's cold, and look inside. With the cap off, squeeze the upper and lower radiator hoses a few times and listen for the sound of coolant rushing in. If there is no sound, there may indeed be a low coolant situation.

Check to see if there is a blockage from the overflow tank to the radiator. Sometimes, the neck at the radiator leading to the overflow tank gets clogged with debris.

Check to see if there is any air in the system, you may just need to burp the system. With the car warm take a set of pliers and open the brass valve located above the water pump for a second for two, than close it. Be sure not to overtighten it, and not to loosen it so far the valve comes out of the body. Do this to the water neck that connects to the upper radiator hose.

Worse case scenario would be having to replace the sensor itself.

 

[dudenamedric]

Thank you for the advice. I'll go check on those!

 

[dudenamedric]

Is there any chance that it was just a fluke reading? I just drove it and had no low coolant light come on.

 

[dudenamedric]

Ok, I have a question about the light itself. I'm not having a problem with overheating or even getting close to overheating. The light seems to flash on and off rather than stay constant. Is the low coolant light supposed to be constant when there's a problem? I just had an issue with my odometer light being dim and that fixed itself the other day, about a day before the low coolant light began to flash. Does this sound like a problem with the light rather than the coolant system?

 

[2000 Buick]

Might be... Try taking it to Autozone or somewhere that will give you a free code scan.

 

[honu]

I own a 1998 Regal GS and some time back, the "low coolant" light came on... per the temp gauge, the engine was not running hot. When I got home, I checked the coolant overflow bottle and saw that the coolant was normal.

After some research, I figured the culprit was probably the "low coolant" sensor in the radiator. I removed it, finding the probe was all "gunked up". I cleaned it thoroughly, re-installed it and the light has gone out.

I did notice the coolant looked "old", like the radiator could use a good flushing and some fresh coolant. I'll be doing that in the next few days.

Thought I'd pass this information on... it was repair that took about an hour to do (including a couple of coffee breaks) and cost exactly zero, the kind of repair costs I like. I'm pretty sure a shop would've, at least, replaced the sensor (at $50.00+ a pop, plus labor) and "found" any number of other problems requiring immediate, and expensive, attention.