Truck wont start

bad bearings on crank or worn oil pump. Pressure will be up when cold, but will drop when engine warms up. Check for knock in lower end. If so, bad crank bearings.

I would want to know what the fuel pressure is on the rail. Sounds like the fuel pressure regulator has failed, or the return line to the tank is blocked.

Knocking in engine and low oil pressure usually means bad main bearings. May have been caused by bad oil pump or just worn out bearings due to high mileage. If this is problem needs engine or rebuild old engine.

Sounds like a piston knock due too not having a oil change previously

Yes, I agree. Overhaul, or new engine time. Loud knocking indicates your crankshaft bearings are toast-it won't be long before a piston rod goes through the block, or the engine siezes up. Overhauling an engine with a bad knocking means a complete teardown and rebuild-very time-consuming, labor intensive, and very, very expensive. You might want to consider a used replacement engine with low miles as a cheaper alternative. Good luck.

Once you run the engine out of oil you damage the bearings that the engine needs to turn and operate smoothly, the bearings are called the rod and main bearings of the crankshaft. At this point the damage is done and hence the noise you hear is a result of the damage. The fix of course is to replace the engine or have it removed from the truck and crankshaft machined smooth again and all the bearings replaced, whether you opt to do this rather than just replace the whole engine with a rebuilt one depends on how many miles on the truck and how often the oil have been changed, it should have been changed every 3,000 miles, if you have not maintained the oil changes then it is a waste of money to repair this engine, just have a rebuilt one installed.

this sounds like the engine oil cooler hose was leaking.

DO NOT run the engine again until you fill with oil.

start the engine and look for the hose that is leaking.

Sounds like a main bearing is spun, or the camshaft bearing is worn out.

If you add an oil thickener it may quiet it down, but that's not a permanent solution if you plan to run it a long time.

I believe there is a knock sensor on this engine causing it not to run. If the knock is too bad it wont run....It actually probably saved your engine....find out why the knock...out of timing?...clogged fuel filter? bad gas? thrown rod?

throttle position sensor