Brand new rebuild with less than 5k in a years time on it giving me the exact same knock as the last engine which blew up shooting a rod after I drove it knocking (it was finished anyway). Only on rpm increase knocking though, not at idle, sitting at idle it loses oil pressure though. This time I parked it. Let me just say water is a factor for certain. With the last engine I was really new to the whole process and while my oil was settled and bag filtered there clearly was suspended water in it. This time it was a combination of absolutely ruthless weather with moisture in smoke so thick that it was sticking to skin in the dense fog. This combined with an almost empty diesel tank and an overburdened diesel filter no doubt caused the problem. Veg oil is very minimal for water now but admittedly perhaps the compounding factor given the problem happened coming off a flush when the fuel is still mixed and an engine up to normal warm but not hot yet.

The knocking is loud enough based the sound to bust a rod just as it did before. But it's hard for me to rule out the fuel system entirely. I've bled up to the injectors and each one is getting fuel but I haven't gone into them yet (I don't have any gauges). So what I'm trying to determine is if there's any possibility that it is a clogged injector resulting from water contamination? Could that cause a severing knock?

The one clue that suggests injection is another time driving about 2 weeks prior to this with the engine hot but solely on veg I got the knock, switched out from veg to diesel and the engine ran fine. At that time the veg filter was nearly clogged too so I chalked that up for the cause and indeed after changing out the filter it ran on veg again until this incident. I did switch over this time again but either there was too much water to right the problem or something more major occurred.

This message has been edited. Last edited by: muzak,

Well the time is up and it's not the injection system at all. My only last theory is that possibly water could briefly clog the injectors enough to rattle the piston off it's bearing in essence. But I'll see soon enough if it is the bearing for sure.

muzak, did you know that water expands about 1200-1?
Meaning when you boil it, a teaspoon of water will expand to occupy a space of 1200 teaspoons.
It happens just slightly slower than the Diesel oil expansion after the compression combustion.

So if you did inject some water along with the diesel the result could have bent the Rod.
It would be similar to injecting Gasoline or Laughing gas in with the Diesel.
The added stress on that piston and rod may have started a sequence that ended with the engine hemoraging the rod.

Do you have a way of checking the compression?
If you have a bent rod now, the compression will be a little less on that cylinder.

One more thought, does your engine have that counter-balance shaft? Maybe its that thing?

I appreciate the response and will get back when I have time thanks.