Coolant issue/possible leak?

My 01 3.4L motor in my truck seems to have a coolant issue. I replaced the rad cap this morning as the gasket material was almost completely gone, but still am unsure where its leaking from. Could be the upper/lower hoses but I feel like I would see coolant leaking from it. I filled it in the reservoir to right at the max line, drove home 30 miles from work, level stayed the same. I parked it, came back 2 hours later and the level had gone down about 1.5 inches. Looked on ground under truck and yeah theres some coolant on ground but not enough to account for the fluid lost since parking. What could possibly be the issue? Is the coolant accumulating somewhere? Planning on taking it to the shop tomorrow for a pressure test. Just hoping to possibly fix it on my own since I'm mechanically inclined. Any advice helps. Thanks

 

Any major water vapour from the exhaust on start up?

 

None at all. Since posting this I actually found the problem. My rad cracked on the very top. About a 7 inch split just to the left of the rad cap...I squeezed the upper rad hose and I could see coolant oozing out of it which all makes sense now because that's where fluid was being "cooked off" and leaving that white residue. Theres spots everywhere on the left side where the crack is. I figure I'll swap the radiator out today myself along with new hoses and cross fingers that was it.

 

Awesome! Way better problem than a head gasket.