Jeep Wrangler TJ 2.5 main bearings, low oil pressure at idle

[Alain_De_Loin]

Hello, I'm new here, although I've had Jeeps for over fifteen years.
I had a problem with the engine head, unfortunately I noticed it a few months too late, in the meantime I had a problem with hoses, clamps and thermostat housing, that's why I noticed it so late.

Never mind, I did the top of the engine according to the rules, I have 12.2 bar compression on each cylinder.

But I noticed some worrying signs with the oil pressure indicator, of course I checked it with a pressure gauge, and to be completely sure I even went to a workshop, they always have professional equipment there.

The results are the same, 27 PSI at idle speed with a cold engine and 5 PSI at idle at operating temperature.
The first thing I did was buy a new oil pump, replace it, and at the same time check the main bearings, unfortunately at the time I did that I did not have the Plastigauge yet.

So I changed the pump, the pressure when cold rose to 40 PSI, unfortunately as it warmed up it dropped to 7 PSI, which is definitely too little.
Of course pulling the throttle caused the pressure gauge needle to jump immediately, which it didn't do immediately with the old pump.
The main bearings don't look too good, but not like they're about to break.
The camshaft doesn't look terribly tired from work, even the hydraulic valve lifters that I replaced because they were already knocking didn't look like there was a huge amount of friction between them and the camshaft.
I'm asking you who have more experience, what's the chance that I'll have to pull the engine to fix a possible problem with the camshaft? The car has 120K miles now, I've had it since it had 62K miles, I change the oil once a year or every 6K miles. When I disassembled the oil pan, I found a lot of small, silver metal shavings at the bottom. As is commonly known, in a Jeep, if you don't lay it on its side, you won't drain all the oil; so these metal shavings could have been there for a long time.

 

[macleanflood]

Why not roll in crank and main bearings? Sure you're gambling on the cam and cam bearings but you'll buy some time for a couple hundred bucks.

-Mac

 

[Alain_De_Loin]

Oh yeah, I forgot to add that I already have new bearings (tri metal) as well as new connecting rod bearings. I can't really afford to change the engine shaft, if you wrote about that, for various reasons that are irrelevant here.

So I'm going to replace all available bearings, unfortunately I have to do it myself lying under the car.

I think that in the first half of march I'll manage to find some time, so then I'll know what's wrong, so for peace of mind I ordered a high volume pump, I know that according to the specification it doesn't fit 2.5 but I'll experiment, it's only less than half an inch more when it comes to the height of the pump.

My question was about how often the camshaft is to blame.

 

[Alain_De_Loin]

There is one more thing, about a year or two ago my old sending unit broke down from age. I bought a Crown replacement and it was fine, before the change I measured the pressure with a manometer and on a warm engine it showed 13 PSI in idle, which calmed me down a bit. Unfortunately Crown is a shitty company and now this sensor is stuck in a certain position and shows pressure around 13 PSI all the time, and connected to a multimeter it shows resistance where with the engine not running it should show zero Ohms. So I don't know how long I drove with low pressure in idle.
Of course, the oil level is normal, I use 10w30 High Zinc and add Ceratec additive for several years.
Every oil change also means using an engine flush.
This car is used by my wife for daily commuting to work, so it is not exposed to huge stress, we prefer a quiet drive, especially in the summer without a roof through the forest.