Oil Gauge acting funny.
So I've had my 99 4x4 FFV for about 2 months now. I decided to change the oil 2 weeks ago. I went with Castrol Syntec 5W30 and a Motorcraft filter. For the past 2 weeks, the engines been running smoother, I've been getting a little better MPG's and it seems to be running quiter as well. All was well until this morning...
I got into my truck and started it up. All gauges went to normal postitions (including the dummy Oil Pressure). I waited for a minute because it was kinda cold here last night (got down to about 45-50) and while I'm sitting there, the oil gauge dropped to nothing. I didn't hear any change in the sound of the engine, and procceeded to shut it off. I waited a couple of minutes, checked for leaks and oil level, and everything looks fine. Plenty of nice clean oil, no drips whatsoever. So I started it up again. The gauge jumped up to the middle, like normal, and stayed there. I drove around a little bit today, and it seems fine. Gauge didn't move, and I just checked the level and it's still normal.
Could it have been a fluke? Or should I check out the oil pressure switch and pump? What would guys recomend I do?