10,110 hours, high fuel

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So I took an oil sample from the Cummins 8.3L in our 821 Case front end loader. We use this loader on our farm mostly for loading the feed wagon to feed the cows. Trying to figure out where this high fuel is coming from. Using Service Pro 15w-40 oil. 370 hours on the oil.

Iron 21
Chrome 1
Alum 5
Copp 1
Lead 0
Tin 1
Sili 4
Sod 4
Pot 3
Moly 101
Bor 12
Mag 896
Cal 1334
Phos 923
Zinc 1119

Nit 21
Oxid 15
Soot .2%
Fuel 5.8%
Vis 12.2

The last UOA I did was back in April and had 320 hours on the oil. Fuel was high in that case as well at 4.6% where most other levels were about the same. I thought it might have been the fuel pump, which is driven off the cam shaft, as I had issues with that in the past which put my fuel over 10%. I replaced the fuel pump but still have a lot of fuel in the oil. This time of year, it idles a lot to keep the cab warm in the winter but I doubt that would cause such high fuel, especially when the last UOA was in the spring and still had high fuel. I had the injectors/injection pump gone through fewer than 3000 hours ago so they don't really have that many hours on them.
 
When did you last have the injectors pop tested and balanced? I bet you have one that is off, causing an issue via washdown in one cylinder.

Still it doesnt look like there is bad wear as a result. Diesel has a bit of lubricity to it.
 
Sounds like a leaky injector to me as well. I would absolutely have them pop tested/adjusted and nozzles replaced if any are leaking, streaming or dribbling - that's a recipe for a melted piston.
 
Kinda what I was thinking too. Like I had stated in the OP, I had them gone through fewer than 3000 hours previously but, who knows on something that old.
 
It could be from idling. 5.8% isn't too too far from the normal 0-2.0% range. If your letting it idle in the cold for extended periods and the coolant isn't staying up to temp and the egts don't stay around 300-400 then the fuel is not burning properly and getting past the rings.
 
All that idling between loads can cause high fuel, especially in the winter. Our old W20 Case Loader would start to "wet stack" if it was left idling out in the bunker for a few hours. We now use a Case 621B to load the mixing wagon and it idles between loads. I do not have a winter UOA on it yet but it seems to burn much cleaner than the old W20.

Something else to consider is the thermostat. Make sure it is working properly and the engine is reaching operating temperature. It might cool off while left idling in cold weather, but should reach operating temperature while being worked.

Do you ever use a diesel fuel conditioner? In my experience it has been very beneficial to our old equipment.

-Rob
 
Perhaps an injector has gone, perhaps not.

The good thing is that the wear was not affected! Good numbers for 370 hours!

If your wear stays this good, after this much exposure, then perhaps the fuel dilution is not affecting things too badly. Certainly need to keep an eye on it, but at this point, it really hasn't done any damage as far as wear goes. Even your vis is not grossly out of whack.

I would agree that no one wants excess fuel in their oil. But the presumption is that the fuel would degrade the oil to a point where it cannot prevent wear. At this point, that's not happening in your case, so no reason to panic. Just keep an eye on it.
 
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How much mess do you got around your crankcase breather tube?

Little to "no" bottom end wear. Looks like the "problem" is around the pistons, rings and cylinders (fuel related of course). It's one of these far from horrible, but not optimal UOAs. Has this one been analyzed by Polaris?

If so, fuel dilution might have been tested with their GC methode, which should be more exact than the IR-test. GC even catches biodiesel. Polaris sometimes reports higher, often truer levels of fuel dilution compared to other labs. You do not use a biodiesel blend, do you?

Thanks for posting another real farm use UOA. We use a Case IH 5120 on an outdoor hog farm = very high idle factor.
 
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Polaris did perform this UOA. We do not use biodiesel. It is kinda messy around the breather tube and they have pointed out slightly high nitration numbers which is san indicator of blow-by.
 
The 5120 is messy too in that area, it has 11,600 hrs. with the original injectors. I am looking for some improved injectors that will fit our duty cycle a little better i.e. more and finer holes, but it's almost impossible to find such info on injectors.

At what speed do you leave the loader idling, around 1200 rpm?
 
Could be. It doesn't have a tach. The throttle pedal tends to stick a little if you don't actually pull up on it with your foot so I wouldn't doubt its right around 1000. Like I said, I once had fuel over 10% when the fuel pump was leaking real bad. Then it was down below .5% for a little while, then it was right around 2% for a couple oil changes then it went up to 4.6% and then the current 5.8%. Each of those OCIs were a little longer than the previous though. I think I'll keep the next oil change a little shorter and then do another UOA in the warmer months to see if the fuel is still high.
 
It's your fuel, but try to idle it a little higher, 1200 - 1300 rpm. Hopefully, the loader has a hand throttle. If not, use the redneckish stick method.

In any case, please keep us updated on this engine and your other equipment.
 
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