Low Oil Pressure Guesses

Oh, now I get it. The ball and spring you refer to is in the oil pump housing. I noticed it when I made the replacement.

Spdloader

Drop the pan and plastigage the bearings. Tell us what you see. You aren't doing it any favors running it like that.

Earle

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That's my plan, as soon as I heal my "wing". I had major shoulder surgery, and I'm in the 4th week of recovery / rehab now.

The Jeep has been relegated to driveway duty since the problem got consistent, wife is rolling the miles up on the Explorer.

Thanks,

Spdloader

That's the sucker. One thought: I replaced the oil pump in my 4L after it dropped something like 15 PSI across the board on one 175 mile run. When I pulled it, it was obvious that the problem was a break in that thin paper gasket between the pump body and the block. Since the old pump had 175,000 miles on it, I went ahead and installed the new one anyway but I later ran a flow/pressure check on the old pump and it was still good - that one leaking gasket was apparently the whole problem. How careful were you about cleaning the surfaces when you mounted the new pump? It could be as simple as that. Small leaks on the high pressure side cause big problems.

Well, I was careful, I did not make it a top priority though. The old gasket came off with the old pump, I wiped the mating surface with a shop towel before slipping the new pump and gasket into place, but that's about it, other than torqueing the pump bolts. I have read before the bulletin about the gasket failure, but the old gasket seemed fine to me. Spdloader

yep - the 2.5L straight 6 in the TR6 has an oil pressure bypass that screws into the side of the block. that's my other toy

reboot

Have you tried to change the oil filter with one of a different manufacturer? You may have a defective one.

It is unusual to have worn-out bearings at 77k miles. I have a '96 XJ with 2.5l, ex-police car with 220k miles on it that has still normal oil pressure. If the car was not extremely abused, or ran without oil, or ran for sustained periods with low oil pressure, then the bearings would not be my first guess.

If you remove the oil pan, you can remove a rod cap to check the condition of a rod bearing. They are the ones that get shot first. If the copper layer is exposed in the rod bearings, then they will need replacement. That's a relatively easy job to do it yourself and replacement bearing shells are relatively cheap. You will need a good torque wrench and a collection of socket extensions to re-torque the rod-caps.

Good luck.

Well, the TJ went off to the dealer, traded in for a brand new '07 Wrangler Unlimited Sahara. She got just what she wanted, she says. We were open with the dealer about the low oil pressure issue, and they didn't seem to care. They really wanted that TJ. So, I don't have any info on the actual cause at this point, they assured me they'd fix it and let me know. Apparently, the son of the dealer wanted our old one, so they are going to fix it.

Spdloader

You didn't have to pay anything? Just traded it in for a 2007? Wow!

Yep, that's it. I still get to drive my '87 YJ, and on occasion, my '86 CJ. Spdloader

Best deal I ever heard of. Amazing!