So Im pretty sure what Im dealing with is the oil pressure sending unit, but I figured it would be worth an ask about my specific symptoms.
Last winter my oil pressure gauge spent about a week reading either way high or way low, basically just being erratic after a period of normal readings. This would happen regardless of if I was at idle or moving. After about a week it leveled off and behaved normal.
Today, about a year later - my check gauges light came on and my oil pressure reads at zero EVEN WHEN DRIVING. My muffler went out literally two days ago (jeeps...) so its hard to hear if my engine is making any unusual noise, but it does not seem to be and I didn't notice any sort of feedback or rough idle. Checked the oil and its right where it should be, although I am past due for an oil change.
If it is the sending unit, is it safe to drive? The sending unit is just sending the info to the gauge, not actually controlling anything - correct?

 

Sounds like a sending unit to me. Verify with a mechanical gauge if that's all it is your fine.

 

I'm not sure you're muffler rusting out is a Jeep thing or not, but metal rusts and mufflers need replaced occasionally. To me, and from your past experience, I would say that you could have a bad ground somewhere. I would start checking all of your engine compartment grounds and clean them up. You don't say where you're from, but I'm guessing you're in a rust belt area from your Jeep muffler experience. If that's the case, then you probably have rusted grounds. Starting there won't cost you a cent.

Oh, and change your oil. If you don't take care of your Jeep, it won't take care of you.

 

+1000 to this. Thinking like this will save you in the long run. I love it when I see guys using their heads!!!

 

Just ran into this on my 00'. Changed out the sensor and it didn't really affect the issue. Coincidently, the check valve in my fuel pump died and I started having other fuel pressure issues. Spent a day cutting off rust tank hanger bolts and putting in a new fuel pump. For some reason changing out the pump fixed both my fuel issues and my oil pressure readings!

Could be luck, but drop by a parts store and borrow their fuel pressure tester for a couple minutes in the parking lot. Might save your brain from melting.

 

So, I put a mechanical gauge on it and after idling in my garage for 20-30 minutes and around 190 degrees, it idled at 10 PSI. On cold start, it was around 60 PSI and obviously got lower with heat. It hovered around 16 PSI for about 10 minutes. Problem?





Sorry. Posted to wrong thread.