My truck is a 95 5.9 4x4 with around 140,000 miles and the oil pressure recently started to drop after Ive been driving for around 10-15 minutes. The pressure is fine (around 40) then when the truck heats up and I accelerate, the pressure will drop very low (15-20) and then for a brief second it will touch zero then come back to normal. My buddy said that there is probably something hitting the screen but we dont know for sure. Could it be a bad pump or just a blockage?? Any help would be of value.

 

Probably the oil pump. Do a search for your problem. Lately there has been a lot of oil pressure threads. Rather then regurgitating whats already been said ten times this week, check out the posts and I'm sure your answers there.

 

for about 60bucks i would just replace to pump( and that with a new plan gasket)

this should help.......good luck
http://www.pavementsucks.com/tech/rearmain.php

 

check your oil!

 

I've replaced the pump twice. The same problem with dropping pressure. The first time at 120k and again at 205k. Solved the problem both times.

 

listen to me when i tell you this, replace the sensor/switch(oil pressure sensor) thats your problem, same thing with my truck, its located in a tricky spot right behind the egr valve, ten minutes of work, goodluck man

 

Yeap... Been there done that once... Picked up a oil pressure sensor and replace it and problem gone. If you got random gauge reading more than likely the sender is shot.