Hey guys, what an awesome forum! All of the information was very helpful when I went to buy my Z28. I've had the car for about two weeks and have noticed that the low coolant light is coming on regularly. I checked both the radiator and the overflow bottle and everything seems fine. The motor takes forever to warm up, but has never overheated on me. I don't know if the previous owner installed a lower-temp thermostat or not. Even if he did, it wouldn't trip the low-coolant light would it? I'm guessing the thermostat is sticking, any thoughts?

 

The low coolant sensor has a habit of getting dirty and giving false indications. You can detach it from the radiator and clean it up & see if it got any better. Also check the wiring connections for corrosion. If still bad, replace the sensor. Also verify if the thermostat is still there, as it is not a good idea to run without one.

 

You can use a coolant system pressure tester to determine if the thermostat is bad. But like he said yes, the GM dexcool is junk and does not last 100,000 miles. If you look inside the resivior tank and there is gunk build up, it is a good indication of having a stuck sensor.

 

Thanks for the quick response! I'll check the sensor first. What would you recommend using to clean it? Should I just wipe it down with a clean cloth, or are there any solvents that would help?

 

I wiped my down and let it soak in some dish soap. Make sure you rinse everything off real good so that way it doesn't contaminate the fluid. How many miles does the car have and what antifreeze? If you do end up replacing the thermostat, drain all the old coolant out and use Prestone's Universal antifreeze, put a new radiator cap on, and have enjoy!

 

OK, now to find the sensor! Where the heck is it? Is it just below the radiator cap, attached to the radiator itself? I'm at work and can't realistically crawl under the car right now. The car has 118k on it, and has green coolant. No idea if it is original coolant or not.

 

It is small square black box attached at the top of the right (passenger) side radiator tank, facing the engine. There a re two wires connected to it.