it started last nite when coming home from work the temp jumped from 210* to 260* in like 3 minutes for no reason as well as smoke from the engine bay. i pull over and the coolant is at a rigourous boil and spewing coolant into the street. then today i popped the hood and saw i had no coolant so i filled it up then drove it around for 4blocks went back home and saw it jumped to 250* and i had no coolant again but there is no leak in the coolant box or pipe to the radiator.

i just want to know what is causingit and how to fix it??

 

Is the coolant overflow boiling even when the coolant gauge is below 210?

 

yes but it is a very slight boil and i took it back to the shop where the guy said it was the fan that was not turning on for some reason

 

Check your fan switch, if it has 1 wire, ground it and the fan should run. If the fan runs pick up another fan switch. Pick up a 180 high-flow thermostat and get a fan switch that comes on at 185-200. Check your cap and if you have not flushed your cooling system for awhile, do it now. Also add a bottle of water wetter and use about 30% anti-freeze to 70% distilled water. Check your hoses and belt(s).