Extremly Low Oil Pressure

[Mudderoy]

Jiffy Lube replaced mine after they broke it off during an oil change.

The girl said "Hey it looks like you have a detenator in here."

 

[JAS]

first off did you move from dino oil to synthetic... that could contribute since the syn tends to flow better than dino oil

second replace the pressure sender unit... it was about a 10 minute job. I had several occasions when my pressure went so low that the check engine light came on.

replaced the pressure sending unit and it runs a nice strong 50PSI when cold and warm idle is nice 35-40 PSI.

 

[4LowandGo]

The oil pressure sending unit is a cheap way to start out. Let us know if that helps the problem.

 

[93_xj]

Ok so some of you might recall I had low oil pressure problems. Alittle history on the jeep. Bought it with 179 on the clock. Didn't begin having this problem until recently around 188k miles.

At cold temp, oil pressure read 40 psi at idle and at 2k rpm. Then when it got hot, at idle it would drop to 10 psi and at 2k rpm it would be a hair under 40.

I said screw it, its not causing me any problems, and I read for every 1000 rpm you need to have 10 psi, so at 800 rpm idle, 10 psi was fine.


Well I was driving today and at 2500 rpms, my oil psi was 20. Not good. I needed to do my 3k mile oil change anyway so I did my oil change and put a new oil pressure sensor in there hoping it was maybe a bad sending unit. Put 5w30 in and everyone said fram blows so I put a purlator in.

Well at cold it does the same thing, 40 and 40. At hot idle, it goes down to 10 again, but at 2k rpms its up to 40.


Something is obviously wrong that its dropping from 40 to 10 between 2K rpms and 800 rpms.


My neighbor and my buddy both suggested I check the pressure relief valve in the oil pump to see if the spring is broken, its a common problem that causes low oil pressure. Any other ideas?

 

[garr]

Put 5w30 in and everyone said fram blows so I put a purlator in.

Any other ideas?

5W-30 is too light for an XJ, 10W-30 is the lighest I have seen recommended for use in a 4.0 XJ.
With your milage I would use 10W-40 winter & 15W-50 summer.

I had my oil changed on my 110K mile 01 XJ in one of those quickie oil change places last year (I was in a rush & never did it again) drove it home, In my driveway the check guages warning light came on & I noticed my oil pressure hovering less than 5PSI at Idle. I called the quick change & asked what they used in my vehicle, sure enough 5W-30!!
It was December so I changed it to Mobil1 10W-40 with a Mobil one filter, Oil pressure after the change at Idle sat at about 15Psi like always.
Problem solved!!

 

[jeepfreak1020]

Mine does it to sometimes. As im idleing it will drop way way low then as soon as i hit the gas it shoots back up?

 

[Big Nick]

Alot of times, as already mentioned, its because of the weight of your oil. As the oil heats up it breaks down and gets thinner causing less pressure. Get a heavier oil and in most cases youll be fine.