What is engine wear really from?

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2,480
I'm beginning to think that wear is truly from using inferiorly thin oils (eg. conventional 5-30) which, with time and HEAT end up forming deposits, tar coatings, sludge, carbon, etc. which start a downward spiral towards preventing oil (even new oil) from flowing, protecting, lubricating vital engine parts because these "deposits" get in the way of proper engine function (engine operation, oil flow and lubrication)....and NOT exclusively this "most engine wear occurs at start-up" phenomenon we were conditioned to believe...unless preceeded by the above engine conditions.
 

MolaKule

Staff member
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21,597
Location
Iowegia - USA
Engine wear stems from surfaces contacting each other. The thinner the oil film (lower viscosity), the more likely the chance of contact under heat (oil thinning) and high loads. I have various papers which show oil film thicknesses under actual engine operation. The oil film may vary from 1.0 um for a 10 weight to 2.75 um for a 30 weight under the same conditions and in the same component. That's why its good to have Friction Modifiers, anti-wear, and EP additives to provide boundary lubrication when the oil film is ruptured.
 
Messages
238
Location
Monterey Park, CA
If everyone would just remember changing their oil in a timely manner, their engines would last much much longer before starting to burn oil. The more I read here, I find synthethics are no different than dino other than allowing extended drain intervals because the oil doesn't deteriorate as quickly as dino. If you do follow the extended intervals it would be wise to have oil analysis to see if your oil is still performing as it should. And don't forget to change your oil filter every 3000 miles if you follow those long drain intervals to keep those abrasive particles from eating away at your engine.
 
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1,874
Location
Ocala, Florida
i've got 7,000 miles on my fram filter with the schaeffers dino oil in it, think i need to change it every 3,000 miles? why? btw, I go along with a lot of what you said. not all but most. good post. [ December 20, 2002, 04:06 PM: Message edited by: BOBISTHEOILGUY ]
 
Messages
238
Location
Monterey Park, CA
quote:
Originally posted by BOBISTHEOILGUY: i've got 7,000 miles on my fram filter with the schaeffers dino oil in it, think i need to change it every 3,000 miles? why? btw, I go along with a lot of what you said. not all but most. good post.
I should have said change the filter at 3000 - 4000 miles if you don't have oil anaylis done. I know in the old days, you change the filter only at the 2nd oil change, but filters are so cheap, and then you get to add another quart of fresh oil! Come to think of it changing the filter is more messy than actually changing the oil, so hope nobody puts it off if you do long oil drains. BTW...thanks Bob for this site! You made me very oil savy!
 
Messages
1,874
Location
Ocala, Florida
your quite welcome. I think we all gain something from here, good and bad. As for the filter, my thoughts are this, if in a regular car/truck engine, you need to change the filter, then time to change the oil. the cost is so minimal for 5qts of oil that if you're getting dirty to change filters, then pull the plug also. I am currently over 7,000 miles on my mineral oil and fram filter and will not pull it until I test it for around 9,000 miles and even then I may not, just depends on the oil analysis I get back at that time. Got some thoughts on this filter issue but not ready to go into it yet.
 

Jay

Messages
1,607
Location
Idaho Falls, ID
quote:
Originally posted by Dr. T: I'm beginning to think that wear is truly from using inferiorly thin oils (eg. conventional 5-30) which, with time and HEAT end up forming deposits, tar coatings, sludge, carbon, etc. which start a downward spiral towards preventing oil (even new oil) from flowing, protecting, lubricating vital engine parts because these "deposits" get in the way of proper engine function (engine operation, oil flow and lubrication)....and NOT exclusively this "most engine wear occurs at start-up" phenomenon we were conditioned to believe...unless preceeded by the above engine conditions.
I disagree. Most wear comes from abrasive wear. Silica is much harder than steel and wins any rubbing contest with any metal in the engine. The wear metal particles that break loose are work-hardened and are abrasive in themselves causing a cycle of wear. The key to long engine life is not thick oil but effective filtration. [ December 20, 2002, 06:56 PM: Message edited by: Jay ]
 

MolaKule

Staff member
Messages
21,597
Location
Iowegia - USA
Wear is from surface interactions (rubbing), which may be caused by too thin a film of lubricant (fluid or solid). Abrasive particles are wear "accelerators." This can be proven by examining the UOA results. What if you took all abrasives from the oil (aka, a perfect air filter)? Would the UOA still show soft metal wear, sure it would. This is because there are situations in which the oil film will rupture and MTM contact occurs, unless you're running a tribological (surface) anti-wear agent in the oil.
 
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