mmmmm.... large sumps.
UOA - Usless Oil Analysis?
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We received some engines from our expedition vehicles that needed to be freshened up. These vehicles had 12 quart wet sumps. The engines lived a hard life getting a major service once a year for 4 years and had about 100k miles on them. The last oil analysis looked pretty grim but when we tore the engine down the actual wear was pretty good. We replaced rings, bearings, seals but almost no hard parts. They were fine. The vehicles were gas engine Toyota Land Cruisers with 4.7 V8's used in Northern Alaska with Pennzoil Platinum 5w-20. The mileage may seen low for a refresh but these engine had between 5 and 6 thousand hours on them in really tough conditions. They were often left idling over night and were also only turned off to gas up than started as quick as both fuel tanks were topped off. I think the large sump and bypass filtration was a big factor in allowing the oil to do it's job.
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I think the large sump and bypass filtration was a big factor in allowing the oil to do it's job.
Without a doubt. Not possible otherwise. That was probably around 300k of severe duty by most convention standards w/75k service intervals. Fuel figures would have been a nice thing to keep track of for comparative mileage figures.
I think that if you wanted to ...and decided to buffer the system even more, you could have probably managed another year before refreshing. I don't know if you could reduce the frequency of service.
I think the large sump and bypass filtration was a big factor in allowing the oil to do it's job.
Without a doubt. Not possible otherwise. That was probably around 300k of severe duty by most convention standards w/75k service intervals. Fuel figures would have been a nice thing to keep track of for comparative mileage figures.
I think that if you wanted to ...and decided to buffer the system even more, you could have probably managed another year before refreshing. I don't know if you could reduce the frequency of service.
There is no such thing as fuel mileage for these vehicles. Some of these vehicles get less than 2 miles per gallon because they are kept running for long stretches of time with very little movement. Sometimes keeping them running is a matter of safety and comfort. The vehicles are never locked and if stopped are always hooked up to a block and coolant heater for the engine and a pan heater for the transmission and one on each differential. If power is not available the vehicle is kept running and the shutters on the radiator are closed. The uoa's we do look pretty ugly but the engine do quite well, considering.
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There is no such thing as fuel mileage for these vehicles.
Perhaps ..but there is surely fuel consumption ...and some mileage figure is registered on the odometer. Fuel consumption is a very good barometer for service intervals since it accounts, to a decent degree, most modes of service. In that 100k over 4 years ..those vehicles consumed a specific amount of fuel and ran for a specific number of hours and traveled a specific number of miles in the process. The hours can't account for the mileage. The mileage can't account for the hours ..but the fuel consumption pretty much doesn't care if you move a foot or idle 24/7. The only thing better would be an rpm counter that you could then index against fuel consumption to show you extreme duty (aka: load).
There is no such thing as fuel mileage for these vehicles.
Perhaps ..but there is surely fuel consumption ...and some mileage figure is registered on the odometer. Fuel consumption is a very good barometer for service intervals since it accounts, to a decent degree, most modes of service. In that 100k over 4 years ..those vehicles consumed a specific amount of fuel and ran for a specific number of hours and traveled a specific number of miles in the process. The hours can't account for the mileage. The mileage can't account for the hours ..but the fuel consumption pretty much doesn't care if you move a foot or idle 24/7. The only thing better would be an rpm counter that you could then index against fuel consumption to show you extreme duty (aka: load).
We use a Hobbs meter for the hours and track the fuel used and the severity of the weather and all together we come up with a schedule for service. So you comments are right on the mark and I agree with you. In less severe weather in a big part of the lower 48, fuel consumption not mileage driven would be a more useful service interval indicator.
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Have you had the notion of posting these UOA for the board to see? I think that would be interesting.
A UOA can be informative, a trend of them more so, but there is still a problem of trying to correlate wear to UOAs. Also, a UOA by itself is perhaps like tyring to troubleshoot an electrical system with only resistance measurements;
I think my voltage regulator might be having problems.
You have come to the right place my son. Brother Allen, bring the holy resistance meter please.
But sir, shouldn't you look at the voltage ?
Worry not my son for we have the knowledge of the alpha and the ohm megger.
Brother Allen, is the regulator the source of this man's troubless ?
It is not, for moderation has prevailed as there is not an excess of resistance.
My son, look elsewhere for the source of your troubles.
I think my voltage regulator might be having problems.
You have come to the right place my son. Brother Allen, bring the holy resistance meter please.
But sir, shouldn't you look at the voltage ?
Worry not my son for we have the knowledge of the alpha and the ohm megger.
Brother Allen, is the regulator the source of this man's troubless ?
It is not, for moderation has prevailed as there is not an excess of resistance.
My son, look elsewhere for the source of your troubles.
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Men of faith
We've gone a few rounds on this. It's been offered that Ferrography would give you what you seek. Far cheaper than the alternative digestion that I've researched. Both will, more or less, read mass.
..but for all its flaws ...the common UOA is all we have to work with.
(said like Yoda when he said to Luke, "The cave ..remember your .."
The lint trap ..remember your failure with the lint trap!
We've gone a few rounds on this. It's been offered that Ferrography would give you what you seek. Far cheaper than the alternative digestion that I've researched. Both will, more or less, read mass.
..but for all its flaws ...the common UOA is all we have to work with.
(said like Yoda when he said to Luke, "The cave ..remember your .."
The lint trap ..remember your failure with the lint trap!
Why is not everyone interested in wear using magnets and looking at what they pick up? They are so inexpensive, can have no negatives effects, and they even "filter" out abrasive ferrous particles.
I user a Filtermag (very effective), MagnaGuard (effective), and magnetic drain plug (effective).
I user a Filtermag (very effective), MagnaGuard (effective), and magnetic drain plug (effective).
Assuming that one is starting with a clean engine Fe from wear ends up in the filter, as particles smaller than what is captured in the filter but not what ends up in a UOA, what ends up iin a UOA, and possibly a bunch of stuff left in the engine. I don't take apart my engines very often or even drop the oil pans, but I do drop the cover on my front and rear diffs to change the oil. Although the oil is pretty clear when I change it, kind of like a darker olive oil, there is a light gray film on some of the parts, parts which I assume are somewhat magnetic and a film which I assume is Fe. A UOA would fall short in assessing how much wear there is. I would assume that some cast iron blocks, heads, timing chains, etc., would do some of the same, and that depending upon manufacturing variation the amount of gray film that might collect would vary.
As previously mentioned 'wear' can be localized, on a part that will render an engine inoperable in short order, or spread out and tolerable for a long time. 'Less' is better is the typical justification, especially in the context of a trend, but it's still probable that it's not a comprehensive indicator of wear due to not collecting the other sources of Fe, and not being able to pinpoint the source of the Fe.
As previously mentioned 'wear' can be localized, on a part that will render an engine inoperable in short order, or spread out and tolerable for a long time. 'Less' is better is the typical justification, especially in the context of a trend, but it's still probable that it's not a comprehensive indicator of wear due to not collecting the other sources of Fe, and not being able to pinpoint the source of the Fe.
1sttuck, your comments are similar to Roy Howell of Redline. In fact, I've read where engines have failed yet oil analysis results came back looking ok. So there definitely appears to be a lot more to it.
As great as this site has been, it's created a "paranoia" to some degree.
As great as this site has been, it's created a "paranoia" to some degree.
Draw a bell curve and plot the wear on any given engine.The greatest amount of wear will occur at startup and then again at shutdown; On the leading and trailing edge.The oil pressure/flow is less than at operational temperature/pressure.Bypass filters have little effect on wear caused by these events.Terry @ Dyson Analysis has commented on this in a post in the recent past.At least this is my opinion, I could be wrong!
The shut down part doesn't make sense. The oil pump keeps pumping until the engine stops turning.
Even if it did stop pumping. There isn't enough time for the oil that was already there to vanish in the second or so it takes an idling engine to stop turning snd the loads are small.
Even if it did stop pumping. There isn't enough time for the oil that was already there to vanish in the second or so it takes an idling engine to stop turning snd the loads are small.
We have enough experience with this stuff that we don't do a lot of uoa's anymore. We kind of know what we are looking at when there is a problem and generally everything works well and a few vehicles are responsible for 90% of the problems. A lot of readings in bad weather are difficult to make anything out of. We hired an expert to interpret the readings. He was of use at the beginning but missed stuff that he claimed he could figure out through analysis. We worry most about sludge and we have gone to a fiber optic scope to look inside. Our large pans that we fabricate all have inspection plates so that you can get inside with very little effort. After 40+ years I can say that the best single thing for an engine that lives a tough life or a long life is a large sump capacity.
I also have a real world example. I used M1 synthetic from early on.
In my Turbo Miata, I had a lead level of around 250, coupled with very low oil pressure. High iron, lead and aluminum made me think the engine was giving up the ghost.
I took it apart, after having an unrelated problem. Guess what? The engine met new specs inside! It was PERFECT, after 120K, it still measured just fine. No wear items needed replacement. Rings, bearings, crank, cam, cylinders were all measuring NO WEAR!
What I did discover is that my turbocharged engines oil was getting too hot here in South Florida.
Chris
In my Turbo Miata, I had a lead level of around 250, coupled with very low oil pressure. High iron, lead and aluminum made me think the engine was giving up the ghost.
I took it apart, after having an unrelated problem. Guess what? The engine met new specs inside! It was PERFECT, after 120K, it still measured just fine. No wear items needed replacement. Rings, bearings, crank, cam, cylinders were all measuring NO WEAR!
What I did discover is that my turbocharged engines oil was getting too hot here in South Florida.
Chris
So...where did the lead come from? Did you drop some bullets into the oil??
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Originally Posted By: theedge67
So...where did the lead come from? Did you drop some bullets into the oil??
The Black Knight: It's just a flesh wound.
So...where did the lead come from? Did you drop some bullets into the oil??
The Black Knight: It's just a flesh wound.
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