the low coolant light is probably a simple float like in a toilet tank. when your coolant is cold it occupies less space as it shrinks. hence may indicate a low level. when it warms up it expands so no indication. it may also be located in a place where cornering or braking might affect coolant level at the indicator float.

good luck. hope it is not the head gasket but it sounds like a good chance it is. i am not sure a compression test would always be a good indicator. of this.

also you may experience bubbles and excess pressure in the cooling system.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.