Oil trouble in my 5.4

[Murph2006]

hey i have a 2000 f150 4x4 with the 5.4 triton, and i am losing oil fast. But the thing is, when its parked for days at a time or even when i park to go in the store, theres NEVER a drop of oil under the truck, and it NEVER smokes at all. But I am losing oil somewhere. I can make some sense of old carbureted motors, but i dont know the first thing about the new stuff. I was on my way to my girlfriends house a few weeks ago, and noticed a red light out the corner of my eye, but when i looked down it went off too quick to see what it was. Well i got about 5 miles on up the road and saw it again and looked down, the oil light was on and the gauge rock bottomed. I pulled in at walmart and shut it down, got out and pulled the dipstick, it was dry, I went in and bought some oil and filled it up, drove it another week, and then parked it to drive my gas saver lol. Well when i went back out sunday and fired it up, it was making awful noise and vibrating bad, i shut er down, got out and pulled the dipstick, dry again, put the last 3 quarts of oil i had in it, and it got it back to nearly normal. Anyone have any ideas where its goin? I owe alot of money on it and i love it anyway so id like to save it if i can lol. Thanks guys

[LxMan1]

Try a new PCV valve first. these have been known to stick and suck alot of oil thru the intake.

[greenego]

How long have you driven it and did it have any maintenance such as an oil and filter change just prior to it starting to lose a lot of oil? It seems very strange that it would just start losing oil this rapidly without any smoke or leaks. Please keep us posted. Have you been under the truck to see any signs of oil on the underbody of the truck?