SFDRookie

i have a 1998 jeep cherokee 4.0 inline 6. when the jeep is cold the oil pressure reads normal then when it heats up and im at idle it drops to zero then i give it gas it goes to normal. If i have my foot on the gas idling at a grand its fine. soon as i take my foot off it will drop to 0 and check gauges light will come on. wondering if any of yall had this problem. Thanks for the help.

4WD4EVER

Very common issue for many of us. Get your hands on a mechanical oil pressure test gauge and check it that way before you do anything else. Let us know what you find out.

nujeepguy

mine would go full scale high. i pulled the sender connector and wiggled it back on.
its good since, contact trouble.

4WD4EVER

That doesn't mean you know the correct oil pressure in the motor; it just means you have a properly functioning electrical circuit from the sender to the gauge.

Outlaw Star

Yes, you still need to do a proper pressure check as well. The sending units are not k own for being real accurate anyways.
OP, you can pick up a oil pressure tester from Harbor Freight for around 12 bucks to do this test.

kc1ble

I also have a 98 with the same issue. I changed my oil to rotella 15w40 and added a quart of Lucas Oil Stabilizer hoping to help with

the problem,
Unfortunately, I hooked up a mechanical gauge and at hot idle it is still only reading 3-4 psi...looks like an engine swap is in my near future, good luck with yours.

BlueRidgeMark

I haven't seen the Harbor Freight gauge, so can't comment on that other than to say HF isn't known for high quality.

You can get a Bosch mechanical gauge for under 20 bucks at most auto parts stores. I got mine from Pep Boys for $16, had it installed and a trustworthy pressure reading in less than 10 minutes. It's easy, it's accurate, and it's peace of mind.

By the way, when I say, "installed", I don't mean in the dash. Just temporarily connected in place of the original sending unit, so I could read the pressure.

extrashaky

I have one. It's actually a pretty good kit. It has a six foot hose so you can drape it across where you can see it while sitting in the driver's seat.

nujeepguy

i drove it home in oct, the gauges looked normal. comments here told me they were 'normal" i trusted them as ok.
about 6 months later the oil went full scale and i did as i said. the reading is the same as it was in oct. im ok with that.
i could question every gauge reading, but i wont.