I bought this truck a few months ago and it had very little oil pressure. I replaced the main and rod bearings as well as the oil pump. Pressure is amazing now.. Warm and at idle, it is about 55 psi. I do know that the timing chain is worn and has some slop. I have the parts and intended on doin the repair this weekend. I have not been driving it much at all with the timing chain play, i didn't want to risk anything. A few days ago, my car broke down and I had no choice, but to drive it to work. I got off the highway and it was missing and has a slight engine noise. There is no smoke and the oil pressure is still great. Checked the timing and it is perfect. I did notice that when I pull the dipstick or take off the oil filler cap, there is a popping sound coming from the motor. It quiets significantly when I put the dipstick back in or the filler cap back on. If I put my finger over the dipstck tube, i notice a slight suction on my finger. Any thoughts? Is my engine shot??

 

It depends on what shot might include.
A compression test would shed some light on what area to do a leak down test on. Once that was done you would know pretty well what needs to be done to correct the problem. Mileage and vehicle condition will have a great bearing on what you decide to do.