Bit of a problem...Once in a while I'll get the low coolant light coming on. I'll let the car cool off and check the coolant level, and its good and the light comes off. Any ideas?

 

Does this happen at all engine speeds or just higher ones? It could be you are just a little low and when you rev the engine it will "lower" the fluid level due to the fact the pump is increasing coolant pressure (same amount of coolant occupying a smaller space).

 

When the engine is cold I check the fluid level in the resevoir and its full. I'll drive around and the low coolant light will come on and stay on. The resevoir is empty at this point. I'll let the car cool off completely, check the resevoir and its full again. Its like theres a valve somewhere getting stuck. Its driving me nuts.

 

On the side of the coolant reservoir there may be two full marks. One for full hot and another for full cold. You may be looking at the full hot mark when the engine is cold and that would be your problem. Note the full cold should be right around the top of the coolant reservoir and the full hot will be closer to mid-bottom.