white....

If it is white, then prepare to dump the car.

if not, run engine until the temp gage is above middle,
check the radiator if is very hot, and if the fan is running.

if the radiator is not hot, take out the thermostat which is at the connection of the upper rubber pipe and engine, replace it;

if the radiator is hot and fan is not running, the fan's thermal switch was broken, get a new one and replace it yourself;

if the radiator is hot and the fan is running, you may need a new radiator or a new water pump, either one will be a little costy.