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Oil pressure too high?

A

Atl-Atl

NAXJA Forum User
Location
Castle Rock
I tried a search but didnt turn up much. Vehicle is a 2000 XJ 4.0/aw4/231. All the sudden the oil pressure is way higher than normal. Idleing it sits at 40-50, on the gas it goes up to about 80. Other than that it seems to be running normally.

Help, thoughts?
 
First, put a mechanical gauge on it to determine if the reading is correct. If it is not, replace the sender--dealer or NAPA unit.

What oil viscosity? What oil filter?
 
I was just going to start a thread as mine is doing the same thing. Now I don't have to. Thanks.

Mine goes off the chart! So you think its the sender?



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Having the needle peg like that is indicative of either a bad ground from the engine to the firewall or more likely a bad sender unit. Rarely is the reading correct.
 
Agreed, my sender on the 91 went from screwy to really screwy, replacing it fixed the problem.

Make sure you get the right sender - there are two, one for idiot lights and one for a real gauge. If you are not 100% clear on which one you want when you talk to the idiot at the parts counter there is a decent chance you will end up with the wrong one.
 
When the sending unit fails, it usually results in "high" readings.

This is most likely the oil pressure sending unit.

I buy them directly from Jeep for best reliability/accuracy/mating with your factory gauge.
 
muddypunk said:
Dont buy napa brand POO made in china turd split down the seem on me and blew out a quart of oil .Good OLD acdelco fixed mine up in five min of hot oil on the side street action
Click to expand...

That sucks....ive never reallly ran into problems running parts from NAPA. I refuse to even stop by autozone or advanced unless im dumpin oil. Most of my OEM stuff i replace is dealer or NAPA like Joe said. Ive heard good stuff about ACDelco occasionally though...

OP and four2score... agree with the rest of the crowd, those are gonna be sending units
 
Looks like its the season for oil psi sending units to check out......thanks for the tip, noticed that mine now reads 80psi a cruising speed today.
 
Mine too. I just dumped a load of money and time into a new h20 pump, radiator, hoses, and thermo. glad it sounds like it'll be a cheap fix. NAXJA coming through, as always, 10 years and running
 
mine's doing the same thing on my 2000. just started doing it today. i noticed that it reads higher than normal, and pegs when its cold. but it does still move (lower at idle, goes up with rpm's as usual) but it just reads too high. I also noticed that if i turned the ignition on but didn't start it, the gauge would read above zero, so obviously its wrong. Checked the ground strap and the plug but they seemed ok. sending unit is my guess. I may give it a couple of days, seems like these thing will straighten out by themselves once in a great while...
 
Another bad one here... Had the jeep last winter and it did fine as far as I remember. Now mine is reading really low, unless engine is under load, it will bounce around the 40s, then tanks out at 0 again. I helped a friend replace one on his 99 with similar problems and it fixed it up. Simple swap of a part.

Isnt there a way to determine if the sending unit is bad with a voltage meter?
 
Replaced the one in my 96 today, got the sensor weeks ago but never got around to it. Was waiting for the rest of the crew to show up for a trail run this morning and tossed it in, the old one was hanging on by a thread and broke in half as soon as I touched it. The hex on the sensor itself is a 1 1/16" or metric equivalent.
 
Mine at idle is 40-50.. goes up at speed never goes above 60 though...

My guess is the oil im running.. I usually change my oil myself but I was in a hurry so i took it to the local oil change place. I told them i run synthetic usually castrol.... They ended up using Castrol Edge 5W-50.....

Im going to change it soon as its past the due date anyway... 5W-50 seemed a bit much to me..
 
old thread but just for future reference, sending unit fixed my problem... i paid to get it from the dealer and it's been working great for a few weeks now.
 
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