I have a 99 3.0 V6. Over the past few days i've noticed that my gauge shows no oil pressure when i start it cold. After warming up the oil pressure pops up to normal. Its more likely to do it the colder it is outside as well. But everytime the truck warms up the pressure comes back. Could this be the oil pump going out? any suggestions what can be done?

Do you notice any different sounds in the engine when it shows no pressure?

I notice no difference at all. The Engine makes no noise difference at all.

i could be wrong, but i have heard that the oil pressure gauge is just a dummy and its supposed to just go to the middle after a min....

The connection to the oil sender unit is corroded or something. Very common, I have that same problem with mine right now. The connection is supposed tucked under the power steering pump.