I have an 01 wrangler Sahara with 58k on the 4.0 have problem: oil pressure is at 40 untill the engine heats up and then hovers around 13. When i am standing still idling for a while at temp it (oil pressure) drops to 0 and the check guages comes on. When I rev the engine the psi goes back up to about 20 at 2k rpm. Is this a oil pump problem or sending unit or what? fresh oil change too no difference. Also is the pump mechanical or electric ( First jeep dont know much but dont want to pad the mechanics pocket) is the part easy to replace?

I have 2 01 TJs' and just recently replaced both sending units for the same reason. Start with that. It's on the block by your oil filter. They gum up and don't read right after time. Replace it with a quality part though. There are some cheaper ones out there but I don't think it's worth the chance.

I've had a similar problem with my 97 for a couple years now, almost exactly as you describe. I haven't done anything about it yet, though.

So can you check the real oil pressure with a gauge? - I have had the six for
about ten years and I have seen alot of oil pumps die - I make it a rule to
replace the oil pump whenever I have the oil pan off - at 100K - or if I get
oil pressure that is lower than 20. I put after market high pressure pumps in
that always put 40 psi in - I have a Cherokee with 300K and it still makes 40 psi
all the time.

Another problem is that the oil filter will be cheap and the back flow will allow
oil to drain out. I have been running dual oil filters for years to avoid the
cheap filter problem. I also use a quart of Lucas in all my engines along with
good oil - using one that does not put alot of paraffin (gunk) in the engine and
use synthetic in all my new engines. If you can use synthetic you will not have the
gunk that builds up on gauges. Since I have an oil pressure port on the external
filter I can check my oil pressure with a gauge any time ... Temp also.

Well, I bit the bullet. For $31 I should just replace the pressure sensor. Easy enough to get to in the 6cyl. Anyone know the torque specs for this, and how, exactly, one might actually get a torque wrench and socket on this thing ?

Torque would be 1 grunt, maybe a little teflon tape also as long as you're careful to keep it out of the oil system.

Thanks Squid !

Boy you sure can't find that thing in the repair manual, nor in the supplement. Just a casual mention in the wiring diagram. What is this, a stealth part ?

Follow up, for the approximately 2.3 people that still seem to be on this forum - I took off my old sensor this weekend, and realized my supplier sent the wrong part. So, I wiped off the old sensor, banged it on my workbench a couple times for the hell of it, and reinstalled it about one turn tighter than it came off. My pressure guage now shows a more normal range. Hmmmmm. Strange beasts these oil pressure guages.

It's the gummed up part of the problem - depending on how much junk you have in the engine - I've seen some really bad engines - then sometimes all the sensor needs is a good cleaning - and a brush on the connector. Maybe some e-grease to make sure it does not corrode. I'll take a clean air can - computer - and try to flush the mounting whole out - but I always check the pressure with my gauge to be sure.

I see this problem enough that I got a oil pressure gauge so I could check - and really know
what the problem was.

Noticed that engines that have been maintained and are running good filers and synthetic oil don't have this problem as often.

My jeep is now 11 years old, my daily driver since 1997 - I guess I can't complain that an oil sensor went flaky.

Got you beat - have a six with 350K an it's 19 years old - the AC just died and I am going to retire it. Had to work on the oil pressure sensor only once - then I switched to good oil and a dual filter - no problem since.

Every few years I pull all my wiring connectors and clean and grease them - that has helped alot over the years.

I put a new valve cover gasket on it a year ago and I used the shop vac to clean out the top of the head - and a strip of black goop came off that was over a foot long... Guess that is want does the sensor up. The pan was really bad also. Took a few cans of cleaner just to cut through the slime one the bottom of the oil pan.

Wow, nice. I've had to replace my AC three times in 11 years, but then again, I have it running 10 months out of 12.

When I pulled the plug on my sensor, it looked as new as if it was still in a box, I was quite surprised. Of course,on the TJ, quite a few of the connectors seem to have some sort of resilient material acting as a seal, built into the plug. Your story about the goop has me convinced to replace my oil pump next time I have to have work done that involves removing the oil pan. Yick.

SOP for any time you remove the oil pan - depending on how much you want to take off the
front end - you have to unhook the cross over arms so the pan can be removed - lower the axle etc - you have to reach in and unbolt the oil pump with its long sump so you can get the pan off.

SOP is to get a high performance - high volume pump - for about twice the price of the cheapy - and put that in - always remember to prime everyting if you can - and clean the pan and sump screen if you are re-using it.