These other guys probably have some better advice but I have something to add

Last year I had strange knocks and sounds during normal driving for a couple days, then one day after truck sat for a couple hours it wouldn't start. I tried everything I could to get it to turn over but had to get it towed home.

The AC compressor seized up, and it was locked solid so the belt couldn't get around at all. You said the AC stopped working which I'm assuming must be the AC compressor, and I bet there's a big gap of potential problems between working fine and completely siezed up.

I was more concerned about cost than having AC so I replaced the AC compressor with a bypass pully that cost 30 bucks and haven't had a problem since.

 

hmm... interesting. The engine noise seems to be coming from the top end, while the compressor is set a bit lower, but still on the passenger side.
Im getting new codes now; P1000, P1635, P1285, P1299. All of which lead to cylinder head issues, so I'm thinking the head gasket may be the issue. I've found a few threads which discuss this, so I'm gonna do some more looking into this... I'm not sure if that explains the knocking though.

 

The p1000 code is a drive cycle code you got that when you disconnected the battery and had the bad connection.. it will go away after you drive the truck

P1236-Fuel pump control out of range - Check your fuel pump driver module ( FPDM ) It may need to be replaced, there is a write up on this forum on how to do it.

P-1285 - Cylinder head overtemp

P-1299 - Cylinder head overtemp protection active

I believe our trucks use some fuel to quench and cool our cylinder heads so if the FPDM is bad you aren't getting enough fuel into the cylinder heads and is causing the truck to go into limp.
Check your fuel pressure and see if it is low, I think you need 30 - 35 pounds with just the key on. Youmight also want to check the CHT switches to make sure they are functioning properly.
Although the lack of codes saying you are running lean or no cylinder miss fire codes Just might mean that I am full of crap and need to be quite . BTW I got the code diffenitions from this site: aboutautomoble.com Good luck and hope this helps

 

that knock you have is the lifters yet. if you decide on a head gasket replacement, check the heads, cams, and guides. also does it smoke at all after this?

 

So I checked for smoke yesterday morning, and it did not smoke at all. I checked the oil again, still no water on the stick.
I took a day off from looking at it so I could clear my head, then I decided to replace the CHT sensor that I had just put in over the weekend (thinking there may be a problem with the new one, and the fact that it felt flimsy when I connected the wire), which turned out to be a good choice since I must have broke it when installing it (one of the two wires in it had broke). So I put the new one in, the connector was sturdy when I plugged in the wire, and now I can't get the truck to crank... WTH.
I decided to go and get a new battery, and I bought one with 850 cold cranking amps... still no crank, the engine rotates, but it doesn't start.

I'm lost at this point. I checked the codes and all I get now is P1000 and P1635... which means nothing apparently. I found out that 1635 just means I forgot to re-adjust the system for the 285 tires that i switched to from 33s. I'm going down the troubleshooting list now to see if anything stands out... so I may just go check that new battery connector...
Any ideas y'all?

 

So I played with the new connector, reset the wires. Nothing. I then cranked the hell out of it and out of anger pressed the hell out of the accelerator... it started. But it ran real rough, took a minute to keep it running, but then it finally idled... sounds like hell. I sat and let it run for about ten minutes and just watched the gauges... sure enough, the oil pressure rose kind of quickly, as well as the temp, but then suddenly the oil pressure dropped and the red light with an oil canister and a temp gauge beneath it lit up. I continued to let it run for a while. then finally shut it down and checked to see if I got any new codes........ Nothing. I tried to start it again... nothing. I'm not seeing anything like this in the Haynes troubleshooting manual, so I'm lost.

 

do a compression test next.

 

Replace the oil pressure sender.

 

" I had it towed home where I checked the oil again now that it was cooled down, and only a sliver of oil was on the stick." -- as stated in your first post.

Like Gotts2BMe mention do a compression test. Silver in your oil is not good.
Last time I had a knocking sound and silver in my oil it was the rod bearings. It wasn't on a truck, but silver color in your oil was probably some metal or coolant mixed in.

I'd drain the oil and see if there are metal pieces/flakes in the oil. Use a magnet and go throug the oil too.

I'd go through everything possible before driving it to far. Last thing you want to do is hurt it more.

Good luck!

 

I believe by a "SLIVER" of oil, he meant that there was only a tiny bit of oil on the stick. Spelling does matter.

 

Just kick me now.

I guess I need some reading glasses

 

Correct, though I will take the advice anyways and skim through the oil with a magnet since the knocking sound may be an indication of warn bearings or what not.


and
Sounds good, thanks. Do you think that a faulty "oil pressure sender" would cause the truck to go into Fail Safe mode?

 

So, after following blind advice and chasing parts for a few weeks. I decided to just take her apart and search for the knocking noise that was coming from the front of the engine. After taking out the front end and the timing cover I found the problem. The timing guides, tensioners, and springs were toast. The tensioners had warn down to the metal, and the guides broke into small chunks that were blocking the screen for the oil, so I replaced them. Truck runs like new!
Future advice for someone who has a similar problem: don't listen to the "Senior Members" who troll around answering post on a whim. Some have great insight, but be careful of those who just bark out quick explanations and tell you what parts to change.
Thank you to those of you who gave thought to your responses. I appreciate your help and will continue to use this site as a resource.

 

So I made a misdiagnosis. It happens. However, I do resent being called a troll for that. NOBODY is right 100% of the time. My percentage would be a LOT better if I actually were looking at your truck instead of going on descriptions over the Internet, which are not always accurate either.