1999 SPORT 80,000 Miles

5w30 Tried Mobil filter vs Fram-- same!

Put 3K miles on since i bought it, AVG 1500 per month.

Fresh oil and filter, since start of problems,

Dropping to 8 on Hot IDLE.

at 1600 only 23 PSI.-- Hot

No noticeable noise, and have replaced sender and used multiple gauges.


Never above 48 PSI at anytime cold. No matter what rpms.

Please help, ive parked it and i know the worse case and the least worse cases, im hoping just a bad relief valve, on the pump.

 

Any chance it could be the sending unit? Do you know anyone with a mechanical gauge that you could borrow?

 

Nope, Already did that today, new sender and a mechanical guage!.
"No noticeable noise, and have replaced sender and used multiple gauges."

 

That's low but not crazy low.

I have a '97 with 202k miles...owned it since new. At hot idle, it will sit on the low side of 10 psi, probably about the 8 psi you are getting. By 1500 rpm, though, it stays right at 40 psi. About the most pressure I ever see at higher rpm is maybe 50 psi.

BTW, my figures are all with 10w40. Last summer, I started getting nervous at the low oil pressure at idle in hot weather, so I went from using 5w30 to 10w40.

FWIW, my Jeep did not and does not have any oil burn or lack of compression. I simply figured that I was loosing a bit of pressure due to the mileage and decided to go a little thicker.

 

Searching will yield faster results. Many issues can cause (have been discussed about) low oil pressure:

https://www.cherokeeforum.com/f2/low...fusion-126237/

https://www.cherokeeforum.com/f2/low...ressure-96842/

https://www.cherokeeforum.com/f2/tim...l-pump-120119/

(my copy/paste finger is getting tired)

I'm really not trying to be a troll here, but searching will yield you many answers MUCH more quickly than sitting there refreshing the page as you wait for answers to a topic that has been discussed (and solved) countless times.

Common causes:

Worn out oil pump (200k seems to be the kill date often, but not always)

Worn bearings (mains contribute to most oil pressure)

Sludge at the sending unit hole

Fram filters (they suck and cause problems)

Faulty sending units (some new units out of box suck)

Problem with gauge itself

Filter/filter adapter leak

The list goes on...

 

Do you think i need a new pump or something?

I just dont like seeing my check gauges light come on.

 

Here's an interesting read.

http://www.jeepforum.com/forum/f19/4...fixed-1304679/

 

Good read!

Im doing that this weekend.

 

I'm not very knowledgeable on the issue so i would be no help but do NOT figure its just the gauge or sending unit. If i goes down to zero PULL OVER.

I have a buddy that blew the motor on his Ford Ranger because he did that exact thing. It went to 0 and he noticed no problems and he kept going and sure enough he blew the motor.

 

Let us know what you find.

 

Your check engine light is coming on?

The highest mines ever been is maybe 48. At hot idle it hangs around 15... Usually just sits around 40 or so. Never had an engine light come on. I thought it was normal for these things to be around 15 - 40 psi?

 

"I just dont like seeing my check gauges light come on."

 

My 98 pretty much the same on low side hot at idle 10psi , hit the gas it climbs to about 40 & stays there under any load. Did sending unit , clean out of sending unit tube good filters 123K . No change . No noise . Never had check gauge light come on. Is idle rpm a bit low ?

 

Alright so dropped the pan found no buildup at all, looked great, tore the pump off and took it apart, looked a little buildup around the oil suck up part but no blockage, pulled A rod bearing and will post a picture soon, i wonder if my pump has a bad pressure relief valve?

 

Replaced pump, all pressure back to normal!