Suspect oil pressure sending unit is going out


TJ Enthusiast
May 18, 2020
Castle Rock Colorado
Just looking for confirmation. I searched on here and believe I have an issue with my oil pressure sending unit.

I was driving home from the car wash after a muddy wheeling trip and on the way home, I noticed my "Check Gauges" light was on. Scanning the gauges, I saw my oil pressure was at 0 (pegged at the L). I was in traffic, so I didn't want to turnoff the engine immediately, but I did turn off my stereo and listen. My top and doors are off, so it's easy to hear everything going on under the hood. Everything sounded normal, but I immediately pulled over and was about to turn the key off when the gauge returned to normal. I turned it off and checked the oil. Normal level and clean. I restarted the engine and the gauge stayed good. I revved it a couple times and all seemed well, so I started heading home. On the way, the gauge started fluctuating like crazy. Usually at normal, but every few seconds, it would drop to 0, then right back up. Once, it even went to H. The engine always sounded and felt normal. My assumption is that if I truly had 0 oil pressure I would have been hearing bad things.

I assume this is the sending unit. Either it got some water into the connection at the car wash, or it was just coincidence that it started right after a car wash and the unit is failing.

Any differing opinions?

I let the Jeep sit outside in the sun for an hour or so, thinking that any moisture in the electrical connection would have time to dry out. Then, I went for a 20ish mile drive, including a run through the gears on a rural road with shift points being between 4k and 4.5k. No pressure gauge fluctuation and the motor pulled as strong as ever.

Must have been water in the connection. I'm picking up a Mopar sending unit though, just in case mine is starting to fail. I found one at a dealership about 40 miles from my house.
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