Low oil pressure during idle

Good morning everyone,

I have a 2001 Cherokee Sport. Yesterday, while idling (vehicle was warmed up) at a stoplight on my way home, my 'check gauges' light came on and I noticed that the oil pressure dropped to zero. Otherwise, everything seemed fine, RPMs were normal, temp ok, etc. Upon acceleration, the oil psi went up to 30 psi and at a stop light, it dropped quite low again.

Fearing a massive oil leak, I stopped and checked it and it was fine. Drove it this morning to work and while the psi did not drop to zero, it was low (10 psi or lower) during idle after warm up.

I am stumped and am thinking that the oil pump or gauge might be shot.

Do you guys have any other ideas?

Thanks,
Andrew
Norfolk, VA

How's your coolant level and condition? Does the oil look like a chocolate milkshake? The 2000 and 2001's are prone to head issues (search "0331 head crack" or something to those terms on here and you'll see what I mean).

It could very well be a faulty gage or sensor as well. I assume you heard no knocking or funny noises when the pressure dropped?

Thanks for the advice.

This Jeep has had continuous issues with the cooling system - the entire system was replaced last year. Pressure checks were done then and no cracks discovered.

Oil was clear and not muddy - I was worried about a cracked head or mixing of coolant. There is no apparent oil leak.

And, when the pressure dropped, there was no apparent outward sign in terms of odd engine noise or failure as I assumed would happen. It seemed to be running fine.

Thanks again,
Andrew

Well in that case, I would look at a faulty sensor, or bad gage. You can get a mechanical oil pressure gage to hook up to the engine to verify that the oil pressure is in fact going that low.

my dad had this problem. his sensor wires got knocked a little loose. the sensor sits right in front of the oil filter and sometimes gets hit when that gets changed. just try checking the sensor connections.

we replace those sensors all of the time. they are cheap and easy to change yourself.

What brand filter you using?

I'll spare the long discussion of any specific brand with a bad rep and just suggest you change the filter to any other reputable make - as long as it's not orange.

Oil filters have a bypass valve to handle high pressure under cold conditions, and also an internal end cap that must retain it's integrity or it will internally dump oil pressure. Some are just glued on pieces of fiberboard that can fail. The most popular - i.e., cheap - brand does that.

You can ask how I know, but just try that first. It's a cheap repair to eliminate that cause - just spin on a quality filter. If the problem goes away immediately, you're cured - unless you take the chance and use that brand again.

Mine did the same thing! change the oil pressure sensor! Cheap easy fix for what looks like a major problem!

change the sensor. Mine did the same so i changed the sensor plus added a mechanical gauge for a back up. FYI just changing the oil to a bit thicker like 10W-30 to 10W-40 greatly helps the somewhat low oil pressure these engines have.