Odd coolant problem? Head Gasket?

[porsche4786]

I recently bought a 1990 Pathfinder SE last Saturday morning. And am having trouble determining if it has a blown head gasket or what. I replaced the valve cover gaskets the same and following day (after I purchased it, took me a day and a half to do the job). Got it all back together, started it up, and I had a pinch in a coolant hose in the rear of the engine (coolant was spraying out). So i went and got a new hose, replaced it and all was fine. I topped off the coolant reservoir and radiator. A couple days later the coolant reservoir was near empty. So I refilled it at work. I went home after work, back to work the next day, from work I drove about 20 miles to a u pull it. Drove back home, about another 20 miles, then after I was home for a while, another 8 miles. Drove to work the next day, coolant reservoir was still full. I drove home, and back to work the next day and the reservoir was half full. I'm not sure where it's going. Maybe a bubble in the cooling system and it's filling it up. There is no coolant in the oil, oil in the coolant, and the coolant doesn't smell like exhaust. It does have steam come out of the tail pipe after start up. Even if the engine is warm during start up (but it hasn't been above about 45 degrees out). When the engine is cold it steams more than if it's already warmed up. But if you drive it, it stops steaming. I have smelt the exhaust, and it doesn't smell like coolant to me. But I have a pretty bad sense of smell. Any ideas? My main thought is that there were/are air bubbles in the cooling system, either from before I got the truck, or while I had it all apart/when it started up and was spraying coolant out from the hose that was pinched.

Edit: There are also no leaks that I have seen. Nothing on the ground after it's been sitting. And it passed emissions the day I bought it.

[kcpath]

put some dye in the radiator...get a blacklight from wally world drive it to normal temp and then check the engine bay with a blacklight. if there is any leaks anywhere the dye will be very bright.

long shot, but check the oil while it cold...make sure its not too runny

if could be a lot of air in your heater core or hoses.

[94pathdestroyer]

I know this may be a dumb question. But did you top off your radiator before you put coolant in the reservoir? Top it off cold, then run your motor and it'll swallow alot of that fluid, and keep topping it off (while running) until it looks like its going to spew all over the place. Then put the rest in your coolant reservoir. Hope this helps.