oil pressure

[jeepster1985]

What is the normal idling oil pressure on the 4.0 HOs. mine is usually running around 60psi, is that normal?

[mudhound32]

To add to the mystery of Jeep oil pressure mine is the original and usually reads no higher then 40 psi. Then in the last month I noticed the pressure would just jump to 60-70 psi at idle or coming to a stop. I though maybe I was low on oil but wasn't the case. Now for the last week or two its back to its old 40 psi. Go figure...

-Mike

[XJ-ARMOR]

Oil press on most 4.0L's is about 60 when cold, but comes down to 40's when in idle and warm.
When hot, press can drop down to 20-40psi in idle. Depending on mileage ect.
Freeway speeds should yield a minimum of 50psi but no more than 75 or so.
Some worn XJ's can idle with as little as 10psi. (250,000 mi)
Rule of thumb: 10 psi per 1000 rpm or 6 cyl.

[jeepster1985]

i guess im fine then i just thought that was a little extreme thanks

[Runnin'OnEmpty]

For those of you who have erratic oil pressure readings, check the sender terminal for looseness. Mine started reading very high, (almost pegged the needle), and the fix was to bend the connector tab a little to get a more secure connection.