When it leaks. If it ain't broke don't mend it
There is a sensor that is in the overflow bottle that may be bad causing the "low coolant light" to illuminate. The coolant level switch is located on the bottom side of the coolant tank. The switch contains a reed switch and a magnetic float. When the coolant level is normal, the float rests away from the reed switch, causing the switch to be open. When the coolant level decreases in the coolant recovery tank below a specified level, the float rests on the reed switch and the switch closes, illuminating the LOW COOLANT light. The coolant level switch is a part of the coolant tank. If the switch needs to be replaced, the coolant tank must be replaced.
Either the cap is bad, your tank is either cracked at the seam or it has a pin hole that you can't see and the coolant is vaporizing ( steam ).
Yes. There should always be some coolant in the overflow tank. Its level should rise when the engine warms up, and it should go back down when the engine cools.
No. It means the cap is not on tight enough. The coolant tank could also have a leak.
your coolant tank should be on the pass. side inner fender
The sensor is located underneath the coolant recovery tank. On a 1999 Cavalier, there could be some sludge built up underneath the tank. Unfortunately the sensor alone cannot be replaced, the entire tank and sensor comes as one piece and must be replaced. tap on the side of your fill/overflow tank where the sensor is located sometimes they get stuck
Tank ling should only be replaced when there is a leak, and in that case it should only be replaced if the tank itself is still structurally sound. Tank lining is one of those things that doesn't have to be fixed unless it's broken. If a tank has been properly lined it doesn't matter if a decade has passed or if its been two decades. It should only be replaced if it's damaged or leaking. You can read about Tank Tech UST Lining.
Bad sensor? Should be located at the bottom of the coolant recovery tank
underneath the coolant tank, it should be easy to see.
Should be at the lower section of the coolant recovery tank
The RX8 has a common problem with the coolant level sensor in the expansion tank. Unfortunately the sensor is part of the tank and so the whole unit needs to be replaced, a fairly easy job to do!
when you open the hood there will be a yellowish white tank near the top left hand corner of the engine compartment. this is the coolant tank. there will be markings on the side for the levls the coolant should be at when the engine is hot and when it is cold. make sure the coolant you put in is the same colour as the stuff in the tank