95 Sub 2500 4X4 6.5 TD

[1electric1]

Ok, so I've got this rig with 141K on it. It has a couple of problems. The oil pressure fluctuates between 40, 20 and 0. I have had a local Mechanic ( not a real good diesel man ) replace the sending unit on my request, it didn't make any difference. I have an appointment with a differnt Mechanic on Thursday the 4th, he wants to do a manual guage test. If he determines that the oil pump is about to go out, what should I think is a good estimate? My other problem is that I am geographically challenged. I live 300 miles from anyone of expertise in diesels. I am apprehensive about driving out of town. Valdez is at the end of the road. I would be in sub-zeroville in an hour and then it's 5 more hours to anywhere. The high pressure fuel pump is suffering also, it really stinks and lurches when in Drive with foot on the brake ( scares the you sh-t out of my wife ).

Thanks-- 1electric1

[rjschoolcraft]

I'm gonna bet that your gage problem is associated with a bad ground. Gear pumps don't do what your describing. If end clearances open up, you can see a general degredation of pressure, but not varying as you described.

If the gage is right, the only thing that can cause those types of readings is running low on oil. If the pickup tube is uncovered, the pump will suck air and the pressure will drop. Then when the pickup is submerged again, it will pump oil and the pressure will increase. Make sure you are not low on oil.

On the surging at idle, have you checked codes from the computer? That could also be ground related, but may be something more serious.