Guessing the same that I found. Timing chain guide crumbled and was sucked into the oil pick up screen. Noise was the timing chain banging on the cover due to slack from the variable timing not working. VCT needs oil pressure for the timing chain tensioners to function.
my oil pressure bottomed out then came back up, i pulled over and checked my oil level and it was fine. i started the truck back up and the pressure was good then it bottomed out again and the engine started tapping then the engine died. i restarted and the pressure was good and parked it real quick. do you think the pump is bad?
The main cause of intermittent oil pressure loss is a pick up screen that is getting debris into it. This is probably beacuse either bearings are worn and maybe one has spun (doubtful, since you'd have more noise), or aluminum / plastic from somewhere in the engine has gotten into the pan, and now is getting sucked into the pump screen. Dropping the oil pan will tell you what may be in there, and sure - you could replace the screen and/or pump, but the question is - where did the debris come from? The timing chain guides could be a source of debris, as well as cam journals in the cylinder heads...
Have you had any other work done on this truck or engine recently?
no other than brakes and tires i really havn't had to replace anything other than the alternator. i changed the oil and filter today and still didn't have any luck so im assuming it is in the oil pan and since it is 4x4 that is going to be a major chore