oil pressure issues-Not the sending unit!

[Showtime3492]

Hey everyone, so my xj has been losing oil pressure intermittently and I know its not the sending unit because I just put 2 new ones on to make sure. So the last one I put on wad from napa cuz I thought advanced gave me a bad part maybe they did cuz the napa one has helped but not cured the issue. Today I was driving approximately 65mph and the oil pressure went down to about 5. Then a few min later came back up to 35-40. After that it danced around between. 10 and 40 for about 20 min till it settled on 40 before I pulled into work. So my plan of action is to run a compression test to check the head for issues etc. Change oil and filter even tho its not due only 1500 miles on it. Now depending on the compression test results what would you think the next step item to check would be. I know it has a few options here to the cause head,bearings,oil pump. What are some opinions on this looking for some advice, stuff I might have forgot to check .info is appreciated THANKS!

-Anthony

[Mudderoy]

Hey everyone, so my xj has been losing oil pressure intermittently and I know its not the sending unit because I just put 2 new ones on to make sure. So the last one I put on wad from napa cuz I thought advanced gave me a bad part maybe they did cuz the napa one has helped but not cured the issue. Today I was driving approximately 65mph and the oil pressure went down to about 5. Then a few min later came back up to 35-40. After that it danced around between. 10 and 40 for about 20 min till it settled on 40 before I pulled into work. So my plan of action is to run a compression test to check the head for issues etc. Change oil and filter even tho its not due only 1500 miles on it. Now depending on the compression test results what would you think the next step item to check would be. I know it has a few options here to the cause head,bearings,oil pump. What are some opinions on this looking for some advice, stuff I might have forgot to check .info is appreciated THANKS!

-Anthony

Any noise associated with the low oil pressure? Something that would confirm the psi you are seeing?

[pvt.tadpolxj]

Could be your dash gauge...But you said your pressure was reading very low..If your motor is not getting very hot at the time of your pressure reading then you proably have good oil pressure...And if you did have very low oil pressure your motor will be knocking enough that it would concern you!...I have found I get better oil pressure more consistantly from using Valvoline oil's. Check out there web site....

[Showtime3492]

No noise from it as far as I have noticed. I'm really not sure though because today it happened at 65 mph an obviously couldn't hear the best. At lunch time I'm gonna run the compression test see what I comebup with..that's in 3.5 hrs so ill post results as long as I get it done. But I'm almost questioning the oil pump in this but Idk how to test it or if you can test it.

[4.3LXJ]

Sounds more like an electrical problem to me. Something is making a lousy contact

[prerunner1982]

Don't take this wrong but have you checked your oil level?

Could be the gauge. If you have $20 for a Mechanical Oil Pressure gauge it might help track down the issue. It would either confirm you have an engine problem or that it is electrical/gauge related.

[Showtime3492]

Sounds more like an electrical problem to me. Something is making a lousy contact

That exact thought crossed my mind about 15 times now. But the sending unit is tight and end connection is in tight. Not sure what else to check... Just had a break at work n had a friend here start it while I looked at the exhaust and there was. ABSOLUTE ZERO smoke on cold start. So I'm beginning to doubt head issues. There was no real noise coming from the bottom end that I could hear

[xj4life2]

I agree with Steve on this one sounds electrical to me bad ground or connection somewhere. But please keep in mind that the 4.0 is known for loosing oil pumps. I would stonly advise you put a real fluid push guage on it and check to be sure.

[Showtime3492]

I agree with Steve on this one sounds electrical to me bad ground or connection somewhere. But please keep in mind that the 4.0 is known for loosing oil pumps. I would stonly advise you put a real fluid push guage on it and check to be sure.

Think that'll be this weekends project to install a second gauge. Then if it loses pressure I'm pretty sure ill be doing an oil pump soon lol. Thanks everyone

[Showtime3492]

So picked up some oil and a new non fram oil filter gonna change the oil after some more trouble shooting see if that helps had the same issues on the way home, got some video of the gauges showing speed, oil pressure and engine temp will post up tomorrow.