Hi...Seems like there is alot of info on here and alot of good help to.I have a ??? about my 2000 XJ.It has the 4.0 in it.My oil presure has went up a lot and I"m not sure whats going on.It use to read 20 if just sitting and 40 going down the road.Now it is 45 sitting and 75 to 80 going down the road.My quess was the sending unit so, I took it off and put a gauge on it.The gauge shows the same thing.I even tried puting a new oil filter on it to see if something was wrong there.I got it with 50,000miles on it and, it now has 120,000.I change my oil every 4,000???How can this happen???Is there any thing bad it can cause??

 

What was the last thng you did before you noticed the psi jump?

 

The last thing I did was change the oil but, that was about 1,500 miles ago and this just started last week.

 

I just started having the same problem. Did you find anything out?

 

Mine has run at 40 idle and 80 at 60 forever and I have 267,000 on the clock , if your worried put a manual guage inline a doulble check it.

 

I think there is a psi releaf valve on the oil pump that is stuck.