no oil pressure when cold
 

Several times in the last month when I start my truck when the engine is cold the oil pressure gauge has idicated no oil pressure. I have seen the gauge jump up after about 10 seconds once. One time I turned the truck off, checked the oil then restarted and the gauge showed pressure. Has ayone ever had this happen? Should I take it to the dealer because it is still under warranty? If it did it every time I would think it would be easier for the dealer to fix/observe but it does not happen everytime. Thanks for any advise.

Probably just the oil pressure sender. The Dealership would have to put a manual guage to verify the proper oil pressure.

Oil Pressure
 

You didn't say what year your truck was, but if it's newer than around 1988 or so, the oil pressure gauge is not a true gauge. The sending unit is an on/off switch that switches at about 5 pounds so the gauge reads either zero or half scale. You either have an intermittant connection to the sending unit, or, more likely, the contacts in the sender are bad, sometimes failing to make good electrical contact. I recommend buying an aftermarket gauge that really reads oil pressure, as the Ford factory gauges are not any better than an idiot light.
Dave

This trouble is probably caused by a defective oil pressure gauge switch. It will be covered under your warranty--if it is still in effect.Have the dealer check SSM ( Special Service Message)14907. New oil switch part number 1U5Z-9278-DA. It is about a 8 dollar part--my 01 Mustang GT did the same thing when it had only 1500 miles. I replaced this switch myself--it was easy to do--the switch is on the side of the oil filter adapter on the drivers side of the engine.