95 atx. So ever since I took the intake manifold off, the temp gauge would creep up to the N or the O, then go back to where it should be, by the M or A. After searching and reading a couple threads on this I concluded that it was not a big deal (air bubble in the coolant?) Today after driving about 20 miles I noticed steam coming from under the hood so I stopped and the coolant was empty. I took the intake off more than 4 weeks ago so why would it do this now? Also, there is no heat inside the car. Any suggestions as to what it could be are greatly appreciated.