When i use the term 'shield', i mean the black plastic/bakelite shroud around the injector not the sealing washer type thing.
New metal seals were fitted but this did not cure the problem.

I could agree on coincidence if just one cylinder was affected but not all at the same time.

What appears to be happening is the injected fuel is burning quickly in the pre chamber before it should (pre ignition).
I noticed there was a slight rise in coolant temperature too, following the fill up with Biodiesel.

I have replaced the pre filter and main filter but there was nothing contained in them to warrant a problem with the fuel supply.

Sounds like leakage around a prechamber. It will make that chuffing sound.

__________________
Doug

1987 300TD x 3
2005 E320CDI

I guess there's two paths to lose compression - one on the outside of the prechamber the between the head and the lockring; the other on the inside of the prechamber through the injector seal and between the prechamber and injector. I'm not sure how tightly the prechamber taper sits against the boss in the head but I imagine the lockring imposes quite a force creating a seal. How that seal can come undone with just a tankful of the worst fuel ever is puzzling. Similarly I don't know how an injector seal can deteriorate over the course of one tankful.

Can you use drops of fuel between the injector and lockring then separately between the lockring and head to isolate the leak?

Sixto
93 300SD

The leak is definately from the outside of the lock ring.
My injectors are the slanted orientation type.

When i said i had just filled up with Biodiesel, i meant just less than 10 miles earlier before the problems started.

I believe the leaks have been caused as a direct result of using the Biodiesel, there is no other explanation.
Somehow the fuel isn't being burnt properly as it is igniting too early in the prechamber or the fuel has caused a problem with either the injectors or the pump.

I have changed both the pre filter and the main filter. Both did not show any signs of blockage or foreign particles.

All the glow plugs are glowing fine as well as the run on period until they are timed out.

This is a link to the area of concern, the prechamber; Help: injector / prechamber / heatshield leak

I need to find the cause of the pre ignition to prevent the excess compression in the pre chambers occurring in the first place.

Next thing to pop into my idle mind is that there was too much gasoline/petrol cutting the biodiesel blend or the pump was mislabeled.

Take some of what's in your filter to be analyzed. Or just smell it.

Sixto
93 300SD

I filled two jerry cans at the same time so i could get that sampled i suppose.
When i got the car home i syphoned off half of the fuel tank and went and filled with normal petro diesel.
Do you think the two will have mixed properly?
I also found that one of the hoses from the pre filter to pump was slightly loose.

Just and update on events.

I have had the injectors tested and they are fine. The pump timing is correct too.

I flushed out he biodiesel,fitted another filter and restarted.
The engine runs significantly better. Only two of the six prechambers are leaking now. Smoke is still evident and smells like and old bus starting from cold.

So it is obvious to me the biodiesel was the problem, the detonation/preignition has damaged the prechamber seals.

The supplier of the fuel has still not replied to my emails or phoned me.

What should i do. Obviously i now need to rectify the two leaky prechambers but surely the fuel supplier has some liability here.

















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