tlgtcountry

Hey guys,

Ive been having some trouble here with my 98 inline 4.0

So im driving home today and stop at the light, oil pressure drops half way.
Kinda scary but i keep it in the middle with the idle and got er home. Messed with the pressure sensor after letting it cool down. Looked fine at start up, then drove it for 15 miles, idled it high. Pressure back down to about a quarter of the gauge after letting off the gas. Im thinking it would have to be the pump, but wanted to ask you guys to see if this has happened to anyone else. I did just change the oil about 2000 miles ago. It is cold up here round 20 and im still using the 10W30 so i dont know if that would make a difference.

ide be greatfull at any help on this subject. Thanks
tlgtcountry

Mattster

Mine sometimes gets stuck off the chart and sometimes will never move off 20psi at all and sometimes it is fine which leads me to suspect the oil pressure sensor is bad. Its possible that your pump is dieing but I would check the sensor or possibly hook up a mechanical gauge to check it as well.

jeeper25

its normal i got 98 also and it does sometimes drops to zero but if you switch to 5w-30 or 20 it shouldnt do it as bad

REWSTER

i have a 00 and it drops bout half way at stops and then go's back up but if it drops all the way to 0 you might have a problem

donnmcc

Oil pressure is made with the tight clearances in the bearings.Hopefully this is a sending unit or gauge.If not replacing your pump probably won't help.

kamokid

try replacing the gauge, ive seen them do that, people replace them and theyre problem goes away

93XJLI

um. oil pressure CHANGES depending on how hard you are on the gas....

this is like the 4th thread on this in a week.

xer0

I had the same problem on my yj, i just ignored it and then a about 6 months i was pcs'ing ( changing my duty station) down to Florida and on the drive started leaking alot of oil. come to find out the oil pressure sensor was shooting oil out like a slit jugular, Easy fix only issue i had was i couldent get a wench on teh old unit so used vise gripes. Cant rember why i had to tho. but that fixed it and i had good oil pressure agian.

tlgtcountry

Thanks guys ill try some things and get back up with you on it.

finneys98xj

the oil pressure guage is there to make you feel good about your motor. 35 is idling on most.

BuckB91XJ

It is always good to be concerned about oil pressure. Good on you for watching your gauges.However, anywhere around 30 at idle is good. The stock oil pressure gauge set up on our XJs is a mere suggestion as to what is actually going on with the motor. If you are anywhere around 30 at idle and 40 to 40+ at highway speed, then you're fine. Your oil pressure sender which is right by the oil filter might be getting gummed. You may want to replace it just to give yourself a warm fuzzy but, I think your Jeep is fine.

tlgtcountry

Thanks guys on gauge readings.
The only problem i am having with the suggestions is that i already replaced the oil pressure sensor. It seems like the oil is getting pumped up in the engine fine but my thoughts are that it isnt coming back down fast enough, keeping the oil up in the top end after letting off the gas.
Im thinking that the strainer might be clogged not letting the oil come back down fast enough. But im not certain because i dont know if its supposed to keep it from coming down or up. What do you think?

Thanks again guys your a great help with this