XJnumber4

So I've been a lurker here for years...simply searching the forums has answered all my questions until now. Great place, for sure.

2000 XJ, 4.0
135k miles
Rotella T6, Napa Gold

I've got low oil pressure across the board, 5 or so at hot idle, won't go much past 30 at 3k rpm. Verified with a gauge. No knocking, chattering, and I can see oil up top if I remove the filler cap. Seems to run fine. I tried another sending unit, just because I had one, no change. Oil level good, with fresh oil. Now the part I'm not sure about....

When I pulled the original sending unit, there was sludgy oil in the inlet. Didn't think much of it, as I had a brand new OEM that I'd thought I'd try. After I tried that new one, with no change, and verified with the gauge, I tried the pipe cleaner in the angle fitting. Nothing. No sludge, no fresh oil on the pipe cleaner that I could see. I had the pipe cleaner going in there a couple inches or so. Can't believe what I found was normal; if it is totally plugged somehow further than the pipe cleaner could reach I suppose that would explain the lack of oil. So I guess the question is "what should I find when I poke a pipe cleaner in there."

And some background here....I don't know much of the history of this Jeep. Long story short, I've had it a month. At the time I got it I had to have a ride ASAP...and maybe, just maybe bought something I should not have. But I'm stuck with it now, for better or worse. Kinda like my marriage!

Thanks for any insight.

PatHenry

When you ran the pipe cleaner, had the engine been running recently? The few times I've pulled the sender I had oil leak out the port every time. I can't remember if any of those times the Jeep had been sitting for some time beforehand.

XJnumber4

Thanks for the reply, PatHenry.

It had been running up to operating temp a few minutes before I pulled the sender.

I forgot to add that in the month I've had it, there has been no coolant loss, and no visible oil scum/slime/choco milk.

The XJ I had before this had not-quite-this-low pressure (10 hot idle, 38 at 2500 rpm) for 3 years and 120,000 miles- I drove it for work, and I drive a LOT for work. So I'm not all that worried about it...but I'm still wondering about the lack of oil at the sending unit.

investinwaffles

I have heard of people using a fitting and a piece of hose to purge a blocked oil sending passage (or confirm flow)

You basically just run the hose to a jug under the Jeep and start the motor, it should pump oil out of sending passage. 5 seconds or so should be all that it takes I would guess

XJnumber4

Thanks very much for that. I'll do that today.

XJnumber4

I hooked up a piece of hose to a bucket and fired it up...in the 5-10 seconds I had it running, it blew out probably close to a quart. So it was either plugged, and now is not, or was never plugged at all. As soon as I can later today I'll top it off and see where I'm at with the pressure.

investinwaffles

Well, it always helps to confirm something 100% and you now know that the port is definitely clear.

Maybe you just have low oil pressure? I feel like mine improved after many oil changes with T6 and Marvel Mystery Oil (though T6 has lots of detergents on it's own). I peeked into the oil pan with a boroscope camera and the crank area and everything was really clean.

I used to see 5-10 psi at hot idle, now I never see it dip below 10 psi even when it's really hot. That is with T6 5w40 and a Napa/Wix 15151 filter


EDIT:
Did any sludgy stuff come out of the sending port, out of curiosity?

XJnumber4

I topped it off, and there's no noticeable change. Guess the port was not clogged, but either way, as you said, good to know 100%. I didn't notice any sludge or anything, but I didn't inspect the oil that closely, especially since there was enough pressure to blow my hose outta the port...yeah, a bit of a mess. But now I know...

I think you're right- I just have low oil pressure. This thing sounds and runs great otherwise, so I'm not worried about it. Especially since the day after I got it, the company I work for finally got me a fleet van to drive around for the job. I went from 500-800 miles a week on the Jeep to probably 40. Pretty sure this one'll last.

I think regardless I'll do an oil change real soon. The guy I got it from said he used T6 (it does have a NAPA filter) and changed it recently, but who knows for sure. I've only put 200 miles on it, but it can't hurt to change it. Good idea about the camera....have a buddy who has one and I'm going to do that.

Thanks again for all the info and tips.

jp

investinwaffles

I completely forgot, check with a mechanical gauge if you really want to be sure. I should have started with that, don't know how I spaced on that

XJnumber4

[QUOTE=investinwaffles;3457732]I completely forgot, check with a mechanical gauge if you really want to be sure. I should have started with that, don't know how I spaced on that


Yup, I did that just about first thing. It read just about same as dash gauge. Thanks for checking though!

jp