Troubling UOA?

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Back story..... 2011 GMC Sierra 2500HD 6.0 gas. 8/2011 Purchased the truck new. 10/2011 Changed out the factory fill and replaced with M1 @ 2122 miles. 9/2012 OC @ 9350m. with PP 7/2013 OC @ 14851m. with PP 8/2014 OC @ 21672m. with PP mods are Black Bear 89 tune and Corsa catback. With only 21,000+ miles and the oil submitted for UOA being only the third OC, is it possible that the wear metals maybe high due to break in? The fuel percentage of 6% is of equal concern. I do a moderate amount of short drives could this be responsible or is the percentage to high indicating a possible injector or tuning problem? Thanks in advance, Ron [img:center][/img]
 
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If you want to have any recourse against the tune company - run another UOA, 1/2 the mileage if you want, see if the numbers are similar, then dump the tune and run a couple more UOAs to verify it was the tune. One datapoint cannot make a trend. Could be a contaminated sample or lab equipment. No way to know with only one datapoint.
 
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High copper in low-mileage engines doesn't bother me at all, the only reason its flagged is because it can show up at end-of-life in older engines with tri-metal bearings when the babbit layer wears through to the copper. In modern engines with aluminum or bi-metal bearings, and frankly even with tri-metal bearings at less than 150,000 miles, I would just assume its due to oil coolers and ignore it. It leaches out of brass/bronze parts like crazy. The iron's obviously cylinder wear with so much fuel dilution. You're washing your cylinder walls clean of oil with that much fuel going past the rings and into the oil so the rings are very starved for lubrication... almost 1 part in 20 of your oil is fuel. My carbureted cars turn in fuel dilution numbers on the order of 1/10th what you're seeing. Get a leaner tune, or go back to stock would be my advice.
 

EastCoastHD

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Thanks for the replies. Yeah, I was leaning towards the tune being to rich. The funny thing is, my mpg's have not changed. 12.5 avg., before and after tune, odd. I'm thinking of going the Blackstone recommended 2000 mile OCI and retest to see if the test was an anomaly. Then return to stock tune and retest again. I will also report the test findings to my tuner, see what he says.
 
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Originally Posted By: 440Magnum
The iron's obviously cylinder wear with so much fuel dilution. You're washing your cylinder walls clean of oil with that much fuel going past the rings and into the oil so the rings are very starved for lubrication... almost 1 part in 20 of your oil is fuel. My carbureted cars turn in fuel dilution numbers on the order of 1/10th what you're seeing. Get a leaner tune, or go back to stock would be my advice.
I agree. Also the viscosity has taken a big hit, perhaps more than just would be explained by 6% fuel. Strangely, TBN has held up well.
 
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I would get rid of the tune. The 6% fuel is a big deal. Should be less than 1%. The iron might be explained by wear due to 6% fuel. You could also have a leaky injector. Do you have an oil cooler? That might explain the copper. If there is no oil cooler you may have a bearing on the way out.
 
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Originally Posted By: EastCoastHD
I'm thinking of going the Blackstone recommended 2000 mile OCI and retest to see if the test was an anomaly. Then return to stock tune and retest again.
Occam's Razor suggests the tune is the culprit. As others have said, the fastest, most direct route is to return the tuning to stock and confirm the problem goes away (or not). But doing another sample at 2000 miles without changing any engine parameters is testing the test. There is value to testing the test, but that's not where the highest probabilities are at this point.
 

EastCoastHD

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Received a reply back from my tuner today..........
Quote:
Hi Ron, I can understand your concern, however fuel changes of that type or not a part of the tune. It is actually not possible for us to alter the fuel mixture any appreciable amount outside of full throttle. The engine operates in closed loop 99% of the time wherein the O2 sensors will control the fuel mixture and will maintain the "ideal" 14.7:1 ratio. In terms of tuning, fueling is *almost* irrelevant. As long as fuel quantity is sufficient, there is no reason whatsoever for additional fuel, it is just wasteful. I've looked at your tune files and outside of full throttle, commanded fuel delivery is 100% stock. At full throttle, we request less fuel than stock (to reduce waste). The oil analysis results must be from something else. I'll be happy to look at a log file if you are able to collect one.
Based on this response I really don't think the issue is related to the tune. Probably going to stay the course, run the current oil 2k miles and retest. My SIL is a GM tech, I'll probably get it in for a injector leak down test in the mean time.
 
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I'd still suggest dumping the tune and seeing if things improve. The bottom line is this: While under warranty if the situation means going back to the dealer for issues related to an oil problem that caused engine damage and they see you messed with the stock settings you will most likely be left footing the bill. It won't matter what the company that sold you the tuner says. Judging from their wording they're diplomatically pointing the blame in another direction too. Increase in fuel amounts, even slight, or a slight decrease in fuel use is still altering factory settings, and that's probably what the dealership would use if it came down to it. opinions vary.
 
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Aftermarket tunes are rarely fine out of the box for every vehicle/driver. You won't know until you run stock for an OCI. Tunes are used by many stealerships to deny warranty service. Most techs would never even look but when they do they will find it. That poor motor is being WASHED in fuel going by the numbers...
 

EastCoastHD

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Just to update my situation..... I pulled the aftermarket tunes and restored the factory tunes. Performed an injector leakdown @ the fuel rail, no pressure loss. Ran a scan and all fuel trims are within spec. At 2k miles I'll drain and submit for UOA.
 
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