White smoke from exhaust

I have a 97 chevy lumina v6 3.6 the engine was rebuilt so I dont know how many miles it has now, but heres my problem when I turn on my car white smoke will come out of the exhaust pipe not a lot but enough to notice like as if it was winter but it doesn't go away and I also notice that it overheats and that the fans don't turn on at all. I have checked the fuses but they all work I dont know how to check the big square fuses though those are the only ones I didn't check, but white smoke doesn't come out every time I turn on the car maybe 3 out of 5 times it will appear and when it does it does not go away. I have no idea what it could be any advice would help thank you.