Missing coolant

[burnout 180]

I own a 180sx with a ca18det engine with some upgrades. However some strange problem just began happening with my cooling system in the last two days. I was driving home from school ( in traffic ) on monday when i noticed some steam coming from under my hood. When i got home i noticed that the coolant in my resivour was bubbling with steam coming out of it so i took off my radiator cap and all that came out was steam. i refilled the radiator which was practically empty turn on the car checked for leaks and i found none.

So the next day (tuesday) i checked the coolant again before i went out and it was still full so none leaked out over night which confirmed that there was no leak. When coming home from school that day same thing happened again steam coming from under the hood resivour bubbling and hardly any coolant in the radiator.

Anyone has any sugestions as to what might be the cause for the coolant to vanish with out any trace?

[burnout 180]

I forgot to mention that there is a trail of dried up coolant coming from the resivours over flow which leads me to thing that the coolant over flowed out of their but what would cause that to happen. My radiator cap is old so i'm going to change that to see if that helps.

[180fan]

sounds to me like you got this thing handled

other thing to check is if you're burning coolant