I have had this 97 Cherokee for several years. When I first bought it we started getting the check gauges light and showed zero oil pressure. The sending unit was very new looking, which scared me and had me thinking I bought a Jeep with a bad motor. Turns out aftermarket sending units only last months at best. The Mopar one has lasted for years but is now failing. Is this a common problem? Anything to help it last longer? It doesn't help that they put it hovering above the oil filter. Will the ones from NAPA last longer than the cheaper ones?

 

When what I am assuming was the original in my '00 finally gave out I bought a Napa one.
The Echlin line one.
While I believe that you should use Mopar sensors whenever possible an oil pressure sensor is an easy job so....
It just started acting up after a lot years. 12 if I had to guess.
And frankly I don't believe it is the sensor but the wiring to it.

 

I had an NAPA Echlin oil pressure sensor on my old '97 XJ 4.0 and it worked great for 5 years - then the jeep got totaled.

 

Yes, it’s a common problem aftermarket oil pressure sending units often fail quickly. The Mopar one is more reliable but still doesn’t last forever. NAPA’s better-quality units might last longer than cheap ones, but they’re still not as good as Mopar. The location near the oil filter exposes it to heat and vibration, which doesn’t help. If you want it to last, stick with Mopar or try to shield it from heat if possible.

 

I have had the NAPA one on my Jeep for years now. Someone will call me out for blasphemy, but I refuse to spend the money for Mopar sensors on a vehicle that is 25+ years old. I put on whatever I find locally, or on rockauto. I haven't had an aftermarket component fail prematurely yet to where I even considered Mopar.

 

I bought the NAPA sensor back when I started this thread. Just put it in and the oil pressure shows good some of the time but eventually goes low again. Up until I changed it had been driving while showing zero oil pressure. What else could it be? Wires? Dirty connector? I was out of electrical cleaner when I installed it.

 

Have you check using a mechanical pressure tester? If you verify you have good oil pressure, then you can focus on the electrical stuff. Of course, if you really had zero pressure, the engine would be toast by now.

I've seen posts where they put a T fitting in between the sensor and port, then attach a mechanical gauge to the T port like below. I know the pic is not a '97 but you get the picture (pun intended)

 

It's just luck of the draw with these things. I had a MOPAR one last only a few months, but the shelf brand one that I replaced it with has been going strong for 9 years now.