ORIGINAL: 5.0stanger

Well, it is normal for coolant to come out of the radialtor, hence the PSI rated radiator cap, that is the purpose of the overflow, but an excessive amoutof pressure will make it spit out more than normal causing you to have a lower than normal coolant level. The extra pressure can be caused be a few things, simplest would be a bad cap(simulating extra pressure by opening too soon) or stat not functioning properly allowing the coolant to heat/expand more, or a blown head gasket(which I experienced) that blows compression past the gasket into your coolant causing extra pressure.

I would begin by adding an overflow, it should level out because it can only expand so much under normal conditions, meaning you shouldn't keep losing coolant if you get it just right. If you keep filling your overflow(which I did with my blown headgasket, overfilled it all over the motor[>:])there is a problem. I would also add a new cap. If your problem keep up, it may mean somethingworse.