Jinma 284 diesel. Blew an injector seal. Picture...questio

It uses a copper seal like a banjo fitting does to seal the bottom of the injector in the block. Look at this one. At the three o'clock position it's blown right through. I have a new injector coming, but is this a symptom of something else that needs fixing?

Check the gasket surface where it seals in the head too, it must be clean and not burned away. You may just need a new gasket if the injector checks OK. If the injectors are not tight in the head that can cause what you have also..

(quoted from post at 15:22:29 06/23/16) Check the gasket surface where it seals in the head too, it must be clean and not burned away. You may just need a new gasket if the injector checks OK. If the injectors are not tight in the head that can cause what you have also..

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Good point about the surface. I figured that I should clean it, but I should also inspect it for any types of anomaly that could allow a little bit of blowby that could grow into what happened here.

Tightening the injectors into the engine is a little tricky. There are two long studs that stick out of the engine at each injector port. The injector just plugs into the port, then a oval-shaped plate is slid down over the end of the injector. It rests on a shoulder of the injector body and has two holes that line up with the studs.

You then put a nut and lockwasher on the studs and tighten down that oval plate...which pushes on the shoulder of the injector...which tightens the tip of the injector against the copper seal in the bore.

The free length of the studs from the head to the shoulder of the injector is maybe an inch and a half. So...it seems as though there is quite a bit of room for the injector to tip ever so slightly and for the quality of the seal to not correlate very well with torque.

I have a torque spec, but I'm going to double-check by feel and maybe re-torque either if I think I hear a little compression leak or maybe after a few hours of initial operation.

Doesn't seem very foolproof to me.