I was getting a little knock even though I rebuilt my injectors about 5k miles ago with Monarks, so I decided to open it up and have a look. After all I had a set of new German Bosch nozzles lying around doing nothing anyway. All seemed fine until I got to injector #4, which had a very black, carbonized injector nozzle up the whole nozzle body when I took it out. Also, the crush washer was charred and burned through in the thinnest parts. Very bizarre. So I rebuilt and balanced a set with the German Bosch nozzles and the knock is now gone.

So what does this mean?

I can confirm the following, by the way: Monarks do certainly have a finer mist spray pattern than Bosch, for whatever it's worth.

KenB
1980 300TD

Something is up with that Cylinder. What it is I dont know, but something is amiss

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hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

It means combustion gases were passing the injector seal.

Either the seal was reused or improperly installed.

Yeah, that's what I'm thinking. It wasn't reused. I did it and used all new ones. But improperly installed? Well, I suppose it's possible I didn't seat it right somehow or it was a faulty seal? Could be. Mine was more uniformly black than in your picture but you've got the idea.

Could it be that the prechamber is plugged up? Not that I'm jumping to conclusions but is it possible to replace prechambers with the head in place?

Thanks,
KenB
1980 300TD

x2 what jt20 said.

Either the Heat Shield never sealed right or something happend to the Nozzle (bad spray pettern or dribbling due to a bad seating area between the Pintel and the Nozzle Body) and Fuel was getting on the Heat Shield and burning there.

The above assumes the Prechamber Ring is still tight.

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84 300D, 82 Volvo 244Gl Diesel

this is an excellent point.


It is possible to replace a PC with the head in place. But a 'clogged' PC would be causing some other disastrous issues.

Tightening up the collar, following what Diesel911 said, is a great idea in addition to general cleaning before install.

The last issue I would raise, is that the injector tips erode.

Using the heat shield with a smaller inner diameter on an eroded nozzle will cause sealing issues.

The shield with a larger inner diameter should be used when installing an injector with a worn tip.