View Full Version : new oil pressure sender. got a question or 2

May 11th, 2012, 14:44
I recently installed a Borg Warner Oil Pressure Sender on my 96 XJ.
The old one read about 40 at idle cold 25-27 hot idle and 45-55psi at speed under load. When revved up (quick "almost" WOT about 2/3) the psi would go to 55 at it's peak cold. Same max psi revved hot. It started to leak and I replaced it with the BW.

The new sender reads just 50-55 cold and 35-40 hot and around 60 under load.
When revved it peaks about 65 or 70 then back when cold. peaks 60 revved hot.

Is that a normal read?
I'm just wondering if I screwed it in too tight or if that matters.
There's about 1/2-3/4 of a thread showing. Hand tight then about a turn more on install.

Do these readings sound accurate?
The engine is in awesome condition and a year ago I had a mechanical oil psi gauge hooked up that matched the new sender's readings almost exactly. (48 cold, 37 hot, 70 hot rev peak, 63 revved hot peak)

It's just after 4 or 5 years of the old numbers it's a drastic change. Everything seem right?

Johnnie Walker
May 11th, 2012, 17:08
I want to say min spec is 10psi per 1k rpm hot? If your current is same as mech gauge should be fine.

May 12th, 2012, 16:39
I've seen different readings from different manufacturers.

The bottom line is IF you are in spec. And you are well within spec. The oil pressure specification for the Jeep 4.0 is as follows:

*Not less than 13 psi at HOT idle
*Between 37-75 psi over 1600 rpms

You have plenty of pressure. Don't worry about it. Enjoy your XJ.