Amsoil 15w-40; 9.5k mi; 6.0 PSD w/ 204k; fuel dilution

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At a real loss on my fuel dilution dilemma, my last sample showed 3.8% fuel dilution at 6k miles so after taking another sample the fuel dilution only raised .6% and that was over a span of almost 4K miles. Now if my understanding is correct this should have tracked even, if it was a cracked head or leaking injectors I couldn't imagine the issue only being sporadic. It's a 2006 F350, 6.0 PSD with 204k miles on it just had the injectors replaced because of severe stiction. Thoughts on if this please. Note: lines 2-3 are the same oil line 1 is from a while back but somehow got put into this group of results

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If I understand correctly, the 2nd and 3rd samples are the same load of lube, right?
I am not clear as to when the injector replacements happened; was it between the 2nd and 3rd samples?



BTW - I updated your thread title to follow our typical convention.
 
Appreciate that! The injectors were changed out before I took the 2nd lines sample. Ran a un sampled oci before that as well. I don't understand how it dumped almost 4% in 6k but only .6% in right around 3k miles. Either way the oil seems to be handling it very good also 2-3 are the same lube
 
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Too hard at this moment to try and pin down a culprit.
I would continue the UOAs and see what the fuel trend ends up being over several successive UOAs.
That one high-dilution reading may have been an error, or a fluke.
Continue to monitor and withhold judgement for a bit.
 
Will do from what you see does the sample still look ok to run? I know ford says up to 8% dilution is ok and it's not seeming to impact the oil a whole bunch
 
I must confess that I've not heard Ford has a statement of allowable fuel dilution. Does not mean you're wrong, just that I've not read it. And given how anal Ford is regarding some of their fluids .... you'd think it would be in print.

8% seems very high to me. However, what is most important is the outputs (the wear trends). The inputs (dilution, vis, FP, etc) are just predictors of potential for behavioral changes. What matters is how it's wearing.

I would think you can continue to use it as long as the wear rates are "normal".
 
I honestly am impressed at how the lube is holding up, not trying to beat the amsoil drum but for almost 5% dilution it seems to be handling things very well
 
Originally Posted by BigShug681
I honestly am impressed at how the lube is holding up, not trying to beat the amsoil drum but for almost 5% dilution it seems to be handling things very well

Honestly, 5% probably is the higher end of what many would find acceptable (tolerable?). But I've seen lots of UOAs where the fuel was 4-5%, and nothing nefarious was happening. That you're impressed with the Amsoil lube isn't so much a statement of brand performance, but just a result of the reality that fuel dilution in MANY application is tolerable up to this amount, regardless what lube is in the crankcase. We see plenty of EB Ford engines with fuel (gas) this high, and wear is fine. I've seen some other diesels with this fuel level, and wear was fine. My point is that you're perhaps attributing a perceived success to a brand, whereas most all lubes in many applications can tolerate up to 5% fairly well without evidence of wear trend shifts.
 
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At what point would you say the fuel dilution will begin to cause increased wear? I know it's a case by case because every engine wears different but I have always been under the perception that fuel dilution will cause increased wear.
 
I would certainly agree that at some point, fuel will cause an uptick in wear. But, until you continue to test it, you'll not know where that point is ....

Don't think that just because your wear may go up a tad, that your engine is going to self destruct and puke itself on the roadside. A logical approach would be to see what your running average Fe/1k mi is. If you can get a few consistent UOAs that show you it's reasonably steady, then use that as a baseline and then continue to extend lube use until you get a significant rise in wear.

Example ...
If Fe is running 2.8ppm/1k miles, and you have a "normal" sigma variation of .4ppm/1k mi, then if it gets up over 4.0ppm, you're no longer "normal" in wear.
IOW ... if your "normal" wear would vary from 2.8ppm up to 3.2ppm for a stdev, then you'd be reasonably safe as it rises/falls centered around that 2.8ppm. But when you see the average start to trend past the second sigma (approximately 3.6ppm/1k miles), then it's time to watch for that 4.0ppm value. Once there, time to OCI.
(all other things presumed to be reasonable in other wear metals ... for the example)

Fuel is just an input to the operational conditions. What we should focus on is wear. Inputs are predictors; outputs are results.
Fuel, vis, FP, TBN/TAN, etc are all conditional cautionary markers, but they do NOT assure wear is affected most of the time. They only note that conditions may change to affect wear in the future. Hence, when inputs shift, it's time to pay closer attention to wear, not automatically OCI.
 
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Originally Posted by BigShug681
Your explanation honestly makes it seem less scary, what's IOW also?


Integrity Operating Window
 
Originally Posted by wemay
Originally Posted by BigShug681
Your explanation honestly makes it seem less scary, what's IOW also?


Integrity Operating Window

Thanks lol still don't understand that but I'm sure I'll be able to find a meaning
 
So a little late but I called Horizon and asked about the oddity of gaining so much dilution the first round and a little over .5% the second sample. They couldn't come up with an answer so they retested it and the fuel dilution had went up to 4.4%, a gain of 1% from the last sample and the Vis was now up from 11.9 to 12.2, the person on the phone said the reason it's showing up now is because they weren't testing for it before! Apparently the computer triggers a GC test when the viscosity drops to a certain point and they tightened the parameters to which it triggers the test. So with the 6.0 shearing the oil on it's own and them having changed the trigger points I now am receiving GC tests, in short meaning this fuel dilution has always probably been there just never tested correctly.
 
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