99XJDad

I searched and couldn't find much. My XJ has 203,xxx miles on it and ever since I've owned it the oil pressure has been great. Normally, it reads 30-40psi at idle, and goes way up at speed. Yesterday "Check Gauges" alarmed me and it started reading 0psi and would only go up to ~30psi max on the highway. My oil level is fine and my engine didn't blow up after driving it home. The sensor seems to be in fine shape along with the wires going to it.

Is my sensor just bad?

Abovetimberline

I would change it before you drive it anymore,It could be bad or maybe something did go wrong,I can tell you the manual says 13 psi at idle and 40-60 at load. Mine idles at 20.
You can also get a mechanical guage.

99XJDad

There's a special socket required, right?

4jeepers

I think that the sensor is bad I have the same problem in my 88' XJ and in my 99' WJ. The WJ likes to read 50 psi with engine off and goes to 80 psi at idle and above! I also have not had any problems in either vehicle!

00XJ

if your going to use a socket you have to use a deepwell but i just used a cresent wrench or pliers. it might take longer but you wont break anything, and its better than trying to find a socket deep enough for it.

00XJ

ya i know when my sensor went bad i was pegged at 80 psi even with just the batt. on. So i dont know about extreemly low psi. but it could be the sending unit. but with the check gauges light on it makes me want to think pressure swith instead of sending unit.

rickybarth

you could try unhooking the sensor and put a little dialectic grease in the connection i did that and now mine works fine

hdhp

I always use a mech. guage on oil psi, water temp and oil temp!

99XJDad

Thanks for all the feedback everyone. Now it only drops to 0 at idle. The engine is running normal.

Gonna try the dielectric grease later.

arsxj

My jeep did this same thing last month. After a while it will always sit at 0psi and never come up. I changed my sender and that didnt fix it. Turns out if your oil is to thin it wont read. I had 5W-30 with 2K on it and it was to thin. Changed the oil to a thicker oil and bam instantly the guage came back up. Hope this helps you.

98 JeepJeep

Hydraulic lifters are great at letting you know when oil pressure is low.....

Also i dont think a deep well will work because the wire connector is wider than the socket area.....they make "sending unit sockets" harbor freight has the set for around 30$

4jeepers

I agree as the 4.0 engine has no problem speaking to you through its valve train!