Cracked 2H injector precup/bore area (1 Viewer)

[ERC]

My 2H had oil and coolant mixing. Tore down the whole thing and head gasket looked fine. Checked out the head and saw each diesel injector precup/bore/port or whatever it’s called are all cracked like the image I attached. Need some guidance here please. Just wondering if anyone has had similar issues and what some solutions are, or if this is even a problem at all. Thanks

 

[mongoose2231]

All 6 of mine were cracked when I took the engine apart for a rebuild. At the time, @Beno was still helping sourcing parts, so he hooked me up with a set. I think you can find them online if you search.

 

[Gimme a 60]

These are notorious for cracking. Anytime you pull the head off of a IDI LC motor, expect cracks in the precups.

This is usually a somewhat serious problem as it’s possible for a severely cracked precup to drop inside of the cylinder, especially if turbo charged. But I’d imagine a lot of peoples are rolling around with cracked precombustion chambers anyways.

You may me able to find some SS precups, and install them. An old LC mechanic told me if you “peen” the precups it’s stops them from cracking, I dunno if that’s true though.

As for coolant mixing with the oil, I’m unsure what can cause that. Cracked head? Oil cooler failure? I’m not sure.

 

[duncanrm]

Your cracked precups (which is almost standard to find when removing a head) wont be the cause of your oil/coolant mix. Close head inspection required, especially if you were actively pushing coolant out and saw bubbles in your radiator etc.. What is the backstory or history?