Engine/Transmission (1994 - 1998) Oil Pressure Drop

[BTanzini]

I was in town 2 days ago and left truck runing, went into store came back out and found that I had no oil pressure registering on dash gauge, yet truck was runing fine,the oil idiot light was not on so I dove home about 23 miles on the way I noticied the pressure gauge would fluctuate form 0 to 40 so I took it easy. I figured the sending unit went out so I replaced it and put a mechanical gauge on also, to be on the safe side, changed the oil which I had planed on doing anyway, started her up and had good oil pressure I thought everything was fine untill today. I went to town and noticed the oil pressure had droped to 25 at idle from 40 and 40 runing, 45 cold. Is there any thing other then cleaning the pressure regulator I should look for? Is this a signal of the oil pump falure? Has any one else had this problem? Thanks for any help in advance guys.

 

[Missouri Mule]

BTanzini, mine will do that when my oil is low. But 25 at idle should be OK, I have forgot what the allowed minimum oil pressure is and will have to look it up.

Is your mechanical guage confirming what the electronic guage is reading?

 

[CumminsPower98]

Minimum Oil Pressure @ Idle: 10 psi

Minimum Oil Pressure @ Rated: 30 psi



Not long ago I hooked up a mechanical test gauge to see what mine was doing since I have the TSB that doesn't allow the gauge to drop below 40 except if it goes below 6 or whatever it is where it will then drop to zero. My hot idle on 15w40 Amsoil was about 20 and rated about 50 if I remember right. I was expecting it to be higher but its still well above spec. I do have nearly 390k miles so I could be loosing a little around the bearings.

 

[BTanzini]

Bill Thomas, thanks for replying. Yes the mech gauge varrifies the electronic gauge. Minimum oil press is 10 psi but to me that seems very low and scarry on a diesel engine.



( Cummins Power98 my oil level is perfect) and it is MOBILE DELVAC what I have allways used from year 2000, 60,000 mi Thanks