Slight Mod to Oil Pressure Sending Unit On '00 XJ

So I have been meaning to check my oil pressure with a mechanical gauge. This is the tool I have to do so.

https://www.amazon.com/OTC-Tools-5610-Trans-Eng-Tester/dp/B000R5G0DO


So as some of you know I always come up with these dumb ideas.

This involves putting in a "T" fitting to make is so I can put the mechanical gauge on the Jeep anytime I want without having to remove the sending unit. I figure I have to pull the sending unit to check the pressure so why not set this up when I do so.
I believe everything to be 1/8" pipe thread. I believe the gauge itself to also be 1/8" pipe thread.

So I am thinking using something like this:

https://www.zoro.com/parker-street-tee-brass-18-in-pipe-vs2225p-2/i/G4582103/

Something like this to plug the opening in the "T" where the mechanical gauge would go when not in use.

https://www.zoro.com/zoro-select-he...MI9sTw45qD3gIVw7fACh2KVwWvEAQYAyABEgL4h_D_BwE

Been poking around and have seen where guys have done similar stuff to run both the gauge in the cluster and a mechanical one at the same time.
I don't see a problem with this.
Am I missing something?

Nothing wrong or unusual about installing a tee.
You can get the tee and plug at any home center, in the plumbing area.

I have a T in mine with a mechanical gauge installed inside the jeep, the sensor still works but sometimes there's 20psi difference between the gauge in dash and mechanical one.

Rick.rob said:

I have a T in mine with a mechanical gauge installed inside the jeep, the sensor still works but sometimes there's 20psi difference between the gauge in dash and mechanical one.

Click to expand...

Little confused. Sometimes but not all the time there is a 20 PSI difference between what your mechanical gauge and the one in the dash says?

So did I rigged up around like the oil pressure sender like I wanted to and checked it with my OTC tester.

So with both the cluster and the mechanical gauge hooked up on start up the mechanical jumped to 70 but settled down to 60 pretty quick. Cluster went to 60 but settled at 52 pretty quick.

For awhile the mechanical was reading a little higher then the cluster gauge. But as the Jeep got hotter then it started reading a lower.

The sensor in there now has been in there for about 3 years. It is the Echlin one at Napa. For the longest time it would read 22ish at a very hot idle. But in the last 6 months I noticed it reading just a little higher.

Anyway to bottom line it. I let the Jeep idle for about an 75 minutes in the driveway. Pressure on the mechanical gauge read about 22. I am OK with that.

Finding the fittings I use for the set up proved to be a little harder then I thought it would be. I figured we would have them at the store but no. Struck out at an Auto Zone and Advance too. Even Home Depot did not have what I wanted. Ended up finding them at O'reilly's.

https://www.oreillyauto.com/detail/...200/4290628/2000/jeep/cherokee?q=209200&pos=0

https://www.oreillyauto.com/detail/...200/4290703/2000/jeep/cherokee?q=227200&pos=0

Ralph77 said:

Little confused. Sometimes but not all the time there is a 20 PSI difference between what your mechanical gauge and the one in the dash says?

Click to expand...

Yes sometimes there is a 20psi difference between the mechanical guage and the gauge on the dash in the cluster.

Rick.rob said:

Yes sometimes there is a 20psi difference between the mechanical guage and the gauge on the dash in the cluster.

Click to expand...

I have noticed that the Napa Echlin sensor I installed about 3 years ago has been reading a little higher then usual starting a couple months ago. Normally 22ish at a hot idle. Pretty much what the mechanical gauge said yesterday. Everybody says to buy Mopar sensors but I decided to chance the aftermarket. Point being that if I had done this about 3 months ago feeling that my cluster gauge and the mechanical gauge were pretty much inline with each other.