I seem to have a mysterious coolant leak that appears beneath the truck at the juncture of the engine and transmission. The color of the leaking stuff has the same greenish look that antifreeze has and it isn't oil when I touch it so I am pretty sure it is coolant. It sort of appears clear unless a drop forms and then it is clearly greenish. The coolant reservoir seems to go down slowly. The exasperating thing is it isn't consistent. The coolant system has been pressurized and nothing shows up. I just drove about 1500 miles on a long trip and nothing seemed to leak out. It almost seems if it sits for a while, like a couple of days, then I notice it. I was wondering if it was a freeze plug but I think the lack of consistency rules that out but I don't know.
2000 Ranger, 3.0L V6, manual transmission, 4x4, about 91,500 miles
Any suggestions? This quirk annoys the hell out of me.