I have an 89' yj, with the 4.2 I6, 200k miles. It was running quite well for about 6 months, with oil pressure right at 40 psi. Let a friend drive it down a dirt road and he got a little rough, after the dust cleared I noticed it had ZERO oil pressure. Took it home and checked with two manual gauges and not even a tick out of the gauge, it just stuck at zero. No play in the crank, so I dropped the pan and put in a new Melling H.O pump. Still no luck. A local shop told me that the 258 is famous for "popping a plug" behind the timing cover, and thats where I should look. I have never heard of this but decided to look.
I took off the timing cover, and I can not find this plug/ oil galley. I was wondering if anyone has some insight on this.
any help would be much appreciated