TERZI1

Hello friends, have a problem..have a 99" F-150, 4.2 6 cyl..initially, about 6 months ago had found coolant in oil..was disappearing very quickly while idling and at normal operating temp..seen coolant pouring out front of engine, so changed timing/water pump gaskets..new everything, including radiator..now, slowly seeing the same thing, only no leakage anywhere visible, and coolant when I open cap, does have pressure releasing from it (not sure how much psi), which would leave me to believe a closed system..but after sitting for a day, coolant level will drop slowly from reservoir. So I am at a loss how the coolant can drop like this if after reaching operating temp and have pressure in system,can drop on it's own. Drove great, no smoke. No oil in coolant, and aware of probs with intake on these engines leaking. Engine has been great till now, which is 230 thousand miles. Any input from you guys would be greatly appreciated.. TERZI1