Chrysler Repair: oil pressure Dodge, oil pressure gauge, wire sensor

Question
I have a 93 Dodge Dakota 318 that the oil pressure has been fluxuating.  Usually it will be normal at start up and 5 to 10 minutes after running it will drop, sometimes to zero.  If I put it in nutral and let it idle it will go to normal.  On longer trips after running 15 to 20 minutes it is fine, however it will drop now and again.  I have changed the oil regularly and have used 20w 50 and 10w 40.  It dosnt run hot, ping or smoke.  Is it as simple as a bad sensor. Thank you
Scott  

Answer
Those sensors are really not that great.  In addition to leaking externally the manor in which they' "measure" oil pressure is bogus.  It's a single wire sensor meaning it can't truly measure a range of voltage.  Instead it's an on or off type switch more or less.  If the pressure drops below a certain threshold then the computer tells you that you've lost oil pressure once it's above that then it actually uses a calculation chart based on RPM, temperature and a few other things to give you a simulated reading.

I would replace the sending unit first unless you have an oil pressure gauge you can run inside the car to actually check pressure while driving.  

If it's true oil pressure failure then you will need to drop the oil pan and check the pan for debris and possibly sludge clogging up the strainer.
Doug