I'd think that oil filter with 100K miles on it is eighter in full bypass or the media is ripped open. If you're going to run the oil for 100K miles, the oil filter should be changed out at least every so often.
Start up wear, Normal wear, and the relation to various oil properties. SAE 2006-01-3414
- Thread starter AEHaas
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Yes, I guess whenever I cut it open, it's gonna be pretty ugly in there, but that was part of the plan.
Frank
Frank
Yes, I know it can happen. My point was I've never seen or have heard anyone say that when tearing down an engine that they have found journal bearings damaged or destroyed by cavitation. If it's happening, it's at a level that doesn't cause any noticably damage and can't be seen. I highly doubt it happens much if any in engines that are force feeding journal bearings with a PD pump.
What surprised me Zee when I searched is cavitation wear happens more with lighter viscosity.
An example of cavitation.
But this is an example of more flow through the bearing is better. The bearing itself is a pump with extreme pressures at MOFT and vacuum behind the MOFT. I guess you have to trust the car engineers. But just thinking out loud… within the temperature expansion of the bearing material there is a minimum, maximum bearing clearance. The modern bearing engineered clearance now is on the minimum side. Could it be because of that low viscosity oil and the cavitation issues associated with low viscosity?
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In: Oil Development for Nascar Racing, Jayne et al. One thing they concluded was that a 10W30 grade synthetic oil performed the same as a 20W50 grade mineral based oil with the same additive package. There was no data of maximum oil sump temperatures in these real engines at maximum load. They did state that, in between test runs, the oil was allowed to cool down to 230F. So that was the starting oil temperature before full loads were applied.
This paper gives evidence of the superiority of a synthetic oil while other studies show no benefit. Nothing is clear cut when it comes to motor oil.
ali
This paper gives evidence of the superiority of a synthetic oil while other studies show no benefit. Nothing is clear cut when it comes to motor oil.
ali
Performed how? Wear? Shear heating? Either one of those would not be expected to be different. What about oxidation resistance or resistance to sludge formation? Or ring sticking or deposit formation?
The force fed oil pressure from the oil pump helps keep the journal bearing low pressure side above a vacuum, which helps mitigate cavitation. If a journal bearing was only supplied by an oil reservoir sitting above it that was feeding the bearing at ATM pressure, the cavitation in the low pressure (vacuum) side of the bearing would be much more likely.
Check out: Oil Flow in Dynamically Loaded Plain Bears, Slaats, WVT 2007.07.
Another study showing start up wear for those who say it does not exist.
Ali
Another study showing start up wear for those who say it does not exist.
Ali
Of course there can be some "start-up wear" in journal bearings for the first few revolutions until the MOFT oil wedge is established from rotation. But when you looked at the number of total rotations of the bearings during engine cranking and firing, vs the total rotations over the life time of the engine, the start-up rotations before the MOFT wedge is established is super minuscule to the point of meaningless.
Going back to used oil analysis (UOA). Many say it is a worthless tool to determine if the use of thinner oils is acceptable in your engine. Often it does not show, or in my case always, that thinner oils result in any more wear. Even when dropping 4 grades below the recommended specification. Yet UOA is very sensitive and has a positive relationship to wear when there is dirt in the oil. I think most or all would agree that as the dirt content goes up the wear goes up in every case. This would make a good study - wear related to the amount of dust in the oil.
Certainly we could go thinner with its benefit of increased power and better fuel economy if somehow filters were Much more efficient. This could be a rather simple solution towards the goal of thinner oil acceptance.
You might think that thicker oil will allow for larger dirt particles but the actual spaces are limited and probably too small anyway.
Ali
Certainly we could go thinner with its benefit of increased power and better fuel economy if somehow filters were Much more efficient. This could be a rather simple solution towards the goal of thinner oil acceptance.
You might think that thicker oil will allow for larger dirt particles but the actual spaces are limited and probably too small anyway.
Ali
Here's an example where just a slight increase in UOA metals turned out to be complete disaster. The UOA didn't really raise any alarms that something major was going on - so more investigations were done. I've seen similar reports from people that had engine problems and their UOA wasn't some gigantic red flag, then they cut open the oil filter and tore down the engine and saw all kinds of major damage. AEHass - do you cut open and carefully inspect your oil filters?
Member @TiGeo here on BITOG went through a similar thing with his VW and found the cam chain tensioner eating itself alive, even though the UOAs were not some gigantic red flag. Maybe he can post some links to this adventures on that. So there certainly are some major limitations to using UOAs to monitor wear.
Note ... the photos don't show up in this article depending on what browser you're using, so use a different browser if the photos don't show up.
reliabilityweb.com
Member @TiGeo here on BITOG went through a similar thing with his VW and found the cam chain tensioner eating itself alive, even though the UOAs were not some gigantic red flag. Maybe he can post some links to this adventures on that. So there certainly are some major limitations to using UOAs to monitor wear.
Note ... the photos don't show up in this article depending on what browser you're using, so use a different browser if the photos don't show up.
Understanding the Limitations of Oil Analysis
Some sealants give false positives of silicates and elemental metals measurements with an ICP spectroscopy are limited to a certain range of particle size, usually four to seven microns. Generally, labs will tell you that parts per million (ppm) numbers in the one or two range can be nuisance...
reliabilityweb.com
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Here's the thread:Here's an example where just a slight increase in UOA metals turned out to be complete disaster. The UOA didn't really raise any alarms that something major was going on - so more investigations were done. I've seen similar reports from people that had engine problems and their UOA wasn't some gigantic red flag, then they cut open the oil filter and tore down the engine and saw all kinds of major damage. AEHass - do you cut open and carefully inspect your oil filters?
Member @TiGeo here on BITOG went through a similar thing with his VW and found the cam chain tensioner eating itself alive, even though the UOAs were not some gigantic red flag. Maybe he can post some links to this adventures on that. So there certainly are some major limitations to using UOAs to monitor wear.
Understanding the Limitations of Oil Analysis
Some sealants give false positives of silicates and elemental metals measurements with an ICP spectroscopy are limited to a certain range of particle size, usually four to seven microns. Generally, labs will tell you that parts per million (ppm) numbers in the one or two range can be nuisance...
Aluminum flecks in oil filter
Cut open my Mann oil filter for my Sportwagen today after changing the oil at about dead-on 5K miles/3 mos. Last UOA showed increased aluminum numbers, it was a mid-OCI UOA after a trip down to GA for a VW event where it was used hard on the roads with "dragon" in the name. Quite shocked to...
bobistheoilguy.com
For me, Blackstone noted the increase in Al but it wasn't a huge increase but enough for me to look in the filter and see all the aluminum glitter. The point is - if you do UOA regularly you can see trends and even seemingly small changes can be worth looking into and not variation in the analysis precision which points back to....you won't know that unless you do these every time and get a dataset going. Here are my UOAs since new on that car (VW Golf Sportwagen):
Note that the silicon is from switching to HPL oil which as ~10ppm virgin if I recall.
That UOA tracking graph also looks like that engine wasn't totally broken in until 20,000+ miles. I use magnetic drain plugs in my vehicles and install them when new, and it takes around 15-20K miles before the collected ferrous material on the magnetic plug goes way down to a low, constant level.For me, Blackstone noted the increase in Al but it wasn't a huge increase but enough for me to look in the filter and see all the aluminum glitter. The point is - if you do UOA regularly you can see trends and even seemingly small changes can be worth looking into and not variation in the analysis precision which points back to....you won't know that unless you do these every time and get a dataset going. Here are my UOAs since new on that car (VW Golf Sportwagen):
If an engine takes that long to break-in, then doing short OCIs and trying to compare wear data on different viscosity oil between two OCIs will be highly skewed by the engine still breaking in. If your engine wasn't totally broken in, it might have been harder to see what was going on.
Blackstone is not worth much in most peoples minds. Terry Dyson is probably the best out there in my opinion. His analysis counts the largest as well as the microscopic particles. Plus, he not only gives you the numbers but a very detailed analysis several pages long on what the results indicate. You need to provide him with information too. It is like a doctor - you have to talk to your patients to get the full story before you can make the best evaluation. Lab values alone cannot give you the best information. Often Dyson will give an audio account as well. It is proprietary and not shown to the general public. If you were to experience these things you would understand the proprietary nature of his revealing work.
I do cut my filters apart when indicated, it is part of the fun. I have appropriate tools for exactly that task. In fact there are very few tools I do not have. I am a tool person. But go ahead and make incorrect assumptions about me since it gives you pleasure. Instead of making conclusions about people you might ask about them instead, very revealing in almost cases.
Often it is best to ask a question rather than make a statement, very hard to do for some people, impossible for others, sad.
Ali
PS: I concur that break in takes up to 20,000 miles, something revealed in UOA. Most people think it is much shorter than this.
I do cut my filters apart when indicated, it is part of the fun. I have appropriate tools for exactly that task. In fact there are very few tools I do not have. I am a tool person. But go ahead and make incorrect assumptions about me since it gives you pleasure. Instead of making conclusions about people you might ask about them instead, very revealing in almost cases.
Often it is best to ask a question rather than make a statement, very hard to do for some people, impossible for others, sad.
Ali
PS: I concur that break in takes up to 20,000 miles, something revealed in UOA. Most people think it is much shorter than this.
Just exactly who made, and what kind of "incorrect assumptions" have been made?
Yes, and doing UOAs before full break-in can certainly skew any kind of accurate wear tracking while changing oil viscosity along the way. Have you ever done any regimented UOA tracking on any vehicles that are fully broken in (20k+ miles) while changing viscosity back and forth after many UOAs?
Working on that one right now but not with that many miles.
Ali
Ali
Could you share with us which oil filtering and air filtering efficiencies you use, and your view on whether you think high efficiency oil + air filters provide the same engine wear or lower engine wear than low efficiency oil + air filters.
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It is my belief that engine wear has little to do with oil viscosity but rather to dirt ingestion. The more contamination, soot and chemical imbalance, the more wear. Use the best oil and air filters possible. Meaning those that remove the smallest particles. Whether you use the same filter over and over again may help them filter better. There is evidence to support this. Because the best way to remove the undesirables is to change your oil more often, I think that is the best we can do. I change my air filter often and my oil filter with every oil change.
Ali
Ali
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