I failed to mention in that this truck had all new bearings and gaskets/seals and oil pump in march of 2005 due to total neglect by the previous owner, now it is having oil pressure problems again withlosing pressure after the motor warms up and sounding like it is out of oil but after shutting off and resting abit the pressure is back for abit then it fails again, am going to have the oil changed again friday to see if that helps any as it did for abit on the last oil change

 

That sounds like it could be so many different things. Blockage of oil routing/lines, oil pump cutting in/out, ect. Is it leaking oil by any chance? It sounds to me, personally, that your oil pump might be going again, but two oil pumps going bad? That is hard for me to believe. Is the truck under warranty? Go to a Jiffy Lube the next time you have your oil change service done and ask them to do a "Motor flush", or whatever they call it. Keep your receipt if you have your warranty, and if it works, great, if not take it with you when you head back to the dealership. If you complain enough, they will not only be forced to delve back into the problem, but will pay for your Jiffy Lube service and your rental car.

Just my $.02