Exhaust has been smoking again. Seems every 150K miles I have to get the injectors replaced. 550K now. Let a friend do it this time. Replaced the passenger side. He found the third one back bad. Put it together and no smoke. Good. 100 miles later I get a low oil pressure. Shut it down and yeah, nothing on the dipstick. He decided it must be leaking out where the dipstick tube enters the block. He thought he fixed it but same thing again.

Forgive my ignorance. Any thoughts?

One more thing. Started idling rough. When he "fixed the dipstick" he tightened up the injectors and it idled fine. Then it started idling rough again about the time I noticed the second low oil pressure indication.