Ford F-150 - 1997-2003 :: Knocking At Startup / Screech On Acceleration

I am going to start from the beginning because oftens times we don't provide all of the information that may be pertinent to the correct diagnosis or repair. It'll be kind of lengthy! It all started about 3 days ago when my wife told me that my truck was "shaking." I said, "ok, just drive the car til' I can look at it" The next morning, the I was able to look at the truck. I had a cylinder 8 misfire detected. I drove it for about 1 hour that day to and from work. I did this so I could see what what the "shaking" was. It was actually what I describe as a "shudder."

Anyways, I done a fuel pressure check and all was well. I took of the coil, tested it, it was fine. So, I took out the plug to inspect it. It was wet! Not drinched, just mildly damp. I dried it off, cleaned it off with carb cleaner and it fired right up no hesitation no nothing. No CEL light, no shaking, no shuddering. It ran perfectly normal. I let it warm up to speed and took it for a test drive around about 6 city blocks. All was well. So I took it on the highway for about a 2 mile stretch. I was givin' her some juice pretty hard to see if it would misfire. Upon acceleration I heard a screech. Now this is where it get's interesting.

The screech that I hear, I just related it to the belt because it's done it ALL the time. When I first bought the truck it squalled like a whipped puppy cause of a cheap belt. The good ol' bar of soap trick fixed that! But, ever since then, it upon shifting, or under acceleration it would screech then stop. So anyways, on the highway run, it screeched while I was accelerating. It did this from about 60mph-80mph. I then, turned around and came back home. By the time I got to the stoplight to turn off towards my house my oil light was on and the engine was knocking. Not a tap, a knock.

I slowly coasted home not going over 20mph and pulling it out of drive as much as I could. I get home, and I check the oil and there is nothing on the dipstick! WTF!? I always run Mobil1 Full synthetic and put it 6qts. It doesn't smoke, doesn't leak or nothing! So I freaked out and went and bought 2 qts of Valvoline Hi-Mi and poured it in. It brought up the hash marks and quieted the deep knock. Later that night after work, I done a full oil change and flush and put back in my Mobil1 Fully synthetic 5w20. It now knocks at startup, and smooths out to a tic. Then at idle, it sounds like a light knock. It appears that it goes away upon acceleration.