First I guess I'll give some history on my truck.

Its a 99 Dodge Ram 1500, with the 5.9l. A kid owned before me, and I trade my little car for it. Its rough cosmetically, but decently low miles (122k) and seems like it has a healthy transmission. I drove it 130miles home, got 14mpg. Figured I'd do some maintainence to it and see if I could improve it some.

I changed the cap/rotor/plugs and plug wires. Did the thermostat and hughes intake plenum kit. Did the transmission pan gasket and filter, adjusted the bands. The truck was running great until today. Although I noticed the last (and the only tank of gas) I put through it I averaged about 8mpg's around town, not running it hard or anything. Although weird, I just figured thats what I get.

Today I drove to a nearby town to do some work (about 20miles down the highway). As I'm exiting the off ramp, I stop at the stop sign, and notice my check gauges light kick on (not until after I stopped). ZERO oil pressure, I sit there stunned for a minute the oil pressure jumps back up to ~30-35psi. I drive to a nearby gas station a few miles down the road, and notice an audible knock from my motor. Sitting idle, I couldn't hear it.

Unfortunately I cant check the oil level in my motor (dipstick is snapped off in the tube), I elect to add a quart of oil. The noise gets less audible. So I add another. The noise is almost gone. I go to work. I leave, and head back down the highway careful not to rev the motor up. Although entering the highway, I hit almost 3 grand with no audible noise. Exiting the highway, audible knock decelerating. Same thing happens, Zero Oil Pressure, and I immediately pull over.

Shut off the motor, let it sit for a few minutes. Start it up. Oil pressure jumps right up for a few seconds and drops back to zero. Blip the gas, oil pressure jumps back up again for a few seconds, and drops to zero. Knock still audible only over ~2500rpm at neutral and ~1500 while driving. I baby it home.

I'm pretty sure that motor is toast, I'm pretty upset. Its not worth dumping the money (nor do I have the money to put) back into for a whole new motor. Ideas? Too early to declare it dead?

 

should have fixed the diptstick...

 

First things first: Get a dipstick in there and while you're there check for leaks, then get the oil level right. Don't even think of going any further until that's done.

If the problem continues after the oil is verified to be at the correct level, stick a mechanical gauge on there to get the real oil pressure because the dash gauges in these critters are no more accurate than any other factory dash gauge. Actual pressure is a very important data point.

It's a good guess that it's not a rod knocking because they'll usually make audible noise at idle or just off idle once the engine is warm. Lifters, though, tend to do okay until the RPM's come up -- and they're cheap enough. So get that oil pressure figured out first and go from there.

 

It wouldnt matter, my truck doesn't leak anything more than a couple drops when parked (if that). There is a leak on the valve covers, but like I said its pretty slow not enough puddle where i park it. The last time I checked it (before I broke it off, doing the intake manifold), it was half way between the marks. I was gonna wait until I changed the oil to top it off (the oil didnt look bad).

I've only driven this truck about 300 miles since I got it (130 miles home).

 

Wrist pin knock, I have seen it before MANY times on the 5.2 and 5.9 motors
caused by running low on oil. I am sorry but it is just a matter of time

 

Doesn't necessarily have to be leaking oil. If the pcv valve is bad, you could be burning it off, and not even notice. That can account for a LOT of oil, in a short period of time.

Get the mechanical gauge, verify pressure after you fix the dipstick. Take it from there.