Water in oil.

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The engine is a 3412c that was bought as a swing engine. No telling how long it had been sitting before we bought it. It had sat in our yard for a few months once it was delivered but it was buttoned up pretty tight.

The graph is backward. The right side was an intial sample pulled prior to getting the engine ready in case we needed it as insurance for another engine. The other sample was about 5 hours on the fresh oil. The oil was changed once more prior to putting it in service.

We ended up putting this engine to work for a very short time but could never get it to do what we needed it to do. The engine that this unit replaced was rebuilt and put back into service.

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First of all, a 5 hour UOA really is too short to make any distinction between the first and second UOAs. There is alwasy some residual and it can taint the view of short OCIs.

That said, 44ppm of Fe after 5 hours is disturbing, but then it's hard to know what is "normal" with this engine. The vis jumps noticibly. The TBN drops dramatically. The boron goes on a factor of about 19x, but the oil was not changed? Same with the Mg; skyrockets with no oil change?

Something is wrong with the engine and something is amis with the report.
 
Interesting report. Definitely "advanced tea-leaf reading." Will this engine be rebuit? If so, it would be interesting to hear the results of a teardown and compare to this UOA. A bit more run time and another UOA might tell more... might even clear up, but it seems as though this engine has some issues if thsi UOA is coupled with your report that it couldn't cut the mustard in service. I'm assuming that the engine as a general type was adequate for the work it was put to but that it was down on power or has some operational difficulties.
 
The report on the right was cold oil from the engine before we started getting the engine ready to put into service. Unknown oil? The oil did appear to be a vanilla looking milkshake. The second one was just delo 400 le with a new filter and 5 hours of runtime to work out some bugs on the engine. The oil and filter was changed again at that point.

We had several issues with this engine and put some resources toward it to try and correct the issues. We decided to get the original engine that this one replaced rebuit and put it back into service once that was done.

Once I can get my sample database network back online I will post samples of the original engine problems and current samples after the rebuild.


By the way. Very soon brand new C-18's will replace these old 3412"s. They are already in the yard.
 
Ok here is the report from the original 3412 that was going bad. We knew what was wrong with the engine and toward the end the problem was getting worse and the gamble was to high so we took it offline for a short while to rebuild(put the engine from the sample above in it's place).

We were able to get @3000 hrs on engine once we started to see the problems. The oil was being changed more often. Extra additive packs were also added. As snake oil insurance
smile.gif
. I had to turn the bypass system off also at one point.

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I'd say you have a clear coolant intrusion, but from where?

You mentioned a rebuild; was it a true tear down with full machining, or just a parts replacement (rings, bearings, etc)? If the surfaces are not true'd, then it's likely a leak across a gasket. If not, then it could be porosity.

Here's what we have to consider. You have coolant in your oil, but do you have oil in your coolant? That would throw other things into the equation.

If coolant gets into the oil, it nearly always has to be at a low-pressure state; 12-14psi of coolant cannot force its way into 60psi of oil lube system. (Unless it's only happening upon shut down, where the oil drops to zero psi immediately, but the coolant system has to depresurize with the slow temp drop of the coolant). So, in a "normally" bad circumstance, the coolant is getting into the oil via a return (low pressure) oil pathway (into the pan, into an oil gallery, etc).

OTOH, porosity leaks can, at times, be sort of a "one way valve" (think like a check valve) where they only leak in one direction. On the surface, it would seem to not make sense, but I've seen it in aluminum castings when I worked at Ford. The pores and grain structure of the metal can act oddly at times. You could check for this leak with air pressure on a sealed oil system, but be aware it may not always reveal the truth. You can pressurize a coolant system for checks as well, but you'd have to do it under the conditions that best mimic operation (full temps, then cooling down, etc).

I would suspect that, if the surfaces are assured good for gasket sealing, you have a porosity leak. Then you'll have to start looking at sources such as the head(s) and the block. To eliminate the root cause, you can "Red-X" the components by a process of elimination by isolating one component at a time. Try swapping the head(s), one at a time, to different engines, etc. See if the problem follows a head, or stays with the block. Also, does it have a liquid oil coolant heat exchager (coolant to oil)? That could be a potential leak source as well.
 
Here is the re-build report.
Ignore the two reports on the left side of the graph as they are from the above replacement engine. Just a unit number issue on my end.

The initial drain was a shop fill of Cat branded mobil oil from the CAT dealership. The current oil fill is Delo 400 LE 15w40.


Remember the last two graph cells only.

4_rig_1_new_build_1.jpg
 
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