Loud Knocking

What would the sound of a bad bearing make in the engine? I have a trerible knocking noise after about 5-10 minutes and then the oil pressure falls off the table. I am thinking that it is a bearing but I have had no water/coolant in the oil. If it could be the oil pump would it make a sound in the engine? I am of course hoping that it is just a bad pump but don't want to take any chances driving it around on a bad bearing.

STOP DRIVING!! Mine did the same thing, and about 3 weeks later, BOOM..it locked up. You don't have to have coolant in the oil to have a screwed up bearing, mine wasnt mixed either, but it had prior to my lockup.

Yeah, just from your description "terrible knocking" I'd say bearing. It's the sound none of us ever want to hear.

Noramally, what all should I get replaced at the same time as the bearing?

Is the rest of your truck in good shape? Do you plan on keeping it for several more years? How old is your truck? Would you perfer to spend several hundred if not a few thousand on this truck or would you prefer to put that kind of money toward another vehicle? You must decide, because you are talking about a major repair.

If I were you , I'd do a complete rebuild since you have to tear it all apart to re-do the bottom end anyhow. Mine had spun 3 bearings, so I just got another engine.

its probably your main bearings gone. After your oil warms it thins and then all you pressure is forced between the worn bearing causing oil pressure to drop because of all the slack from the crank.

there is also a service advisory on this issue for the 04's

pull the engine, get an new crank and bearings, if it is a rod bearing and not a main you will have to take the head off to pull the piston out and change the rod, so I would just go ahead and rebuild the whole engine. How Many Miles are on this thing???