I've had this problem, that is becoming more and more annoying as the days go on. (Truck is a 99 4x with a 3.0)

When I get up in the morning to start my truck up, it could be cold, it could be warm (anywhere from 17degree's to 70 degree's) my oil pressure gauge, takes FOREVER to reach Normal. It stays down on the bottom like it's avoiding the normal section like the plague. Latley it seems that it's taking more and more time to reach Normal. By normal I mean the middle of the gauge. Has anyone else had thie problem? Is there a oil pressure sensor? Good old Haynes doesn't show on 98-00 3.0's the location of such a thing. Anway just thought I'd post up maybe someone else is having the same problem that I am. The gauge works and I know it reads, cause once the truck is warmed up (20 min) oil pressure is where it's supposed to be. But geez 20min? Most engine's make oil pressure in 10-50 seconds wouldn't you say? Any help would be appreciated...

 

The oil pressure guage is actually a dummy guage.It does not read true oil pressure.The sending unit is a pressure switch which actuates at about 7 psi.If yours is slow to operate the problem lies in the guage itself provided the 'Check Guage' light is not coming on.

 

To elaborate a little, the "gauge" really only has two actual functional indications. It will either read nothing or perfect right in the middle. A reading of nothing means oil PSI less than 7. A reading of perfect in the middle means oil pressure greater than 7 PSI. It is really stupid but thats what Ford does.

If your oil pressure is showing ANYTHING other than nothing or perfect in the middle, it is probably a gauge problem. If it stay at nothing then jump to perfect after a while, you could actually have an oil problem preventing the pressure from going up.

 

http://rogueperformance.com/oilsw.html

Made for a '94, but it is the same theory on the later models.