talkinghorse43
Well-known member
Thinking more about the occurrence of injector seal leaks and hold down bolt failures (aka black death), it seemed to me that most cases reported in this forum were from injectors near the front of the engine. If this is in fact the case, then this might mean that the working hypothesis that black death is due to low quality fuel (low cetane) and overpressure spikes during combustion might not be the correct hypothesis. So, to find out if most cases reported were from injectors near the front of the engine, I embarked on a slog down memory lane. I say slog because the only way I could be sure I had found most of the reported cases was to look at every post containing the word "injector" - there were 153 threads containing that word; now 154. I might have missed some because the search engine does not find "injectors" when you search for "injector". Anyway, the results are listed below (in no particular order) with the poster's screen name and the injector # involved:
Steady Eddie - 2
topless - 2
hkpierce - 1 (DAD reading - not Black Death) [HKPierce edit]
cerickson - 2
abittenbinder - 1
solera - 1
abittenbinder - 1
xenox2 - 1
brandon - 2
mean-in-green - 1,2,3
SteveD - 2
t-man - 1,4
05highroof - 1
abittenbinder - 2
Altogether, 14 reports of the black death, and you don't have to use statistical analysis to see that my observation about the black death usually occuring at the front of the engine is correct. Admittedly, this is probably just a small sample of all that have occurred and the sample could be skewed, but the results are pretty overwhelming. Personally, I can't imagine why poor fuel would cause the front injectors to leak and not the back. Unless someone can come up with other data, or explain how poor fuel could force this result, I'd say we need to find another hypothesis about why black death.
If this does hold up, then I can think of another hypothesis that could explain this black death observation and that's rusting of the injector body resulting in locking the injector to the bore in the head. This would force the injector to move in lock step with the head as it expands and contracts with temperature cycling, resulting in either lifting the injector off the copper ring seal, or compressing the copper ring seal and causing a leak on cooldown. This rusting has already been reported in this forum to be more prevalent in the front injector wells by sikwan and jim_wildgoose. Also, inspection of my own engine shows that to be the case as well.
Steady Eddie - 2
topless - 2
hkpierce - 1 (DAD reading - not Black Death) [HKPierce edit]
cerickson - 2
abittenbinder - 1
solera - 1
abittenbinder - 1
xenox2 - 1
brandon - 2
mean-in-green - 1,2,3
SteveD - 2
t-man - 1,4
05highroof - 1
abittenbinder - 2
Altogether, 14 reports of the black death, and you don't have to use statistical analysis to see that my observation about the black death usually occuring at the front of the engine is correct. Admittedly, this is probably just a small sample of all that have occurred and the sample could be skewed, but the results are pretty overwhelming. Personally, I can't imagine why poor fuel would cause the front injectors to leak and not the back. Unless someone can come up with other data, or explain how poor fuel could force this result, I'd say we need to find another hypothesis about why black death.
If this does hold up, then I can think of another hypothesis that could explain this black death observation and that's rusting of the injector body resulting in locking the injector to the bore in the head. This would force the injector to move in lock step with the head as it expands and contracts with temperature cycling, resulting in either lifting the injector off the copper ring seal, or compressing the copper ring seal and causing a leak on cooldown. This rusting has already been reported in this forum to be more prevalent in the front injector wells by sikwan and jim_wildgoose. Also, inspection of my own engine shows that to be the case as well.
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