Low Oil Pressure?

[jay79cj7]

Tire/Hi-Lift Carrier Suggestions

I just retrieved my 79 CJ7 (258) from grandma's garage after a winter of sitting and getting worked on here and there. Its finally summer here in Chicago! I noticed on the 30 min highway drive home that my oil pressure dropped gradually until I was at about 20 at 2500 rpms, and probably about 10-15 at idle. I know that the pressure will drop as the oil warms up, so that accounts for some of it, but it was dropping even after it was warm. I have had the same oil in there since last fall when I put her away for the winter. I know I should change it soon, but my question is, could this old oil have degraded, and therefore I am losing oil pressure, or have I just had another problem pop up on me here? The oil is 10W30. I am pretty sure the gauge and sender work OK. I am really hoping that I don't have to keep a close eye on this now. I just got the transmission to transfer case adapter replaced, the 4x4 vaccum shifter replaced, replaced a spring, etc. It is driving so much better; I hope nothing is wrong with the engine. Thanks guys.

 

[sillsmack]

There is no way of knowing fer sure. 1979 was a lotta years ago so engine wear is not out of the question.

FIRST> perform a LOF. doesn't your Jeep req 10W40? I think 10W30 has only been req just the last few years. There should be a sticker under the hood.

SECOND>connect a mechanical oil pressure gauge to the engine and see what kinda pressure the 258 is making.

If low...well, its like low blood pressure, you need a new heart, er, pump.
And/Or the bearings have become so worn that they are starting to allow too much oil pressure to leak out and well, a rebuild is in order.

 

[jay79cj7]

Ah, I should have mentioned that its a reman engine with 25k or so miles that the previous owner put in. I guess that still doesn't rule out wear, but it doesn't have 100's of k miles on it like some out there. I am hoping that I don't have an issue here. As for the oil, I don't have an owners manual and there are no stickers left under the hood, but my Haynes says 10W30 or 10W40. I have been using 10W30, but I could go 40 next time. Whats a LOF? Thanks!

 

[laneiac]

Clogged air filters

Could the pickup be clogged?

 

[Mike1]

Hi

Had a similar problem, erratic readings on gauge and wouldnt come up at all sometimes. Would work fine on other occasions. It was only the contacts - 2 wires into sender below distributor. Tightened these wires up and all was fine, normal readings again.

Mike

 

[far_right]

thats what mine is appx, and has 30k on a rebuild... jeeps have low oil pressure... i wouldnt worry as long as it doesnt get worse

 

[jay79cj7]

Thanks guys. I'll just keep my fingers crossed and my eyes on it. Take it easy.