Iv recently had the same problem aswell. I was driving and my top radiator hose blew. The temp gauge was only reading half the whole time, there was white and blue/black smoke coming out from under the bonnet, I tried limping it to the next exit as I was on the freeway but the car cut out. Few ours later I checked the dipstick and outside of head of the motor no visual signs of water or oil. Any ideas?