I don't know much about UOAs and I have never had one done. But I have seen many on this site and had a few questions about them. What do you look at when you analyze a UOA? I see they list all these minerals such as iron and sulfur and whatever. Isn't the real important numbers in the viscosity and the TBN after so many miles? Wouldn't those numbers tell if the oil really holds up or not?
Analyzing a UOA
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TBN is a good indicator of oil condition but the other metals play a part in that higher than normal wear metals (FE,CR,PB,CU) may mean a problem that is starting.
Also the metal will show a bad air filter (SI) or anti freeze leakage (NA,BR,MO)
Insolubles will show sludge formation
Oxidation or nitration numbers will also show potential sludge and varnish precursors.
Viscosity will show oil breakdown as in shearing to lower vis grade or fuel dilution or even with high soot or oxidation it will show oil thickening
basicly any change from the new oil profile can be noted and when something is out of range its time for a oil change out or some engine maintnence.
That is why I like also a baseline VOA of the exact oil used since ALL published specs are a "typical or average" data point and
most likley are not the exact PPM numbers in your current oil from the bottle. Sometimes silicone AF maybe used in Motor oils and the amount does vary from batch to batch if you have a batch with a "high" number the UOA will flag SI and say you have a air filter leak when you do not.
As a basic bench mark to oil changes TBN retention is as good as any mark to make a change out decision I like TBN to retain at least 20% of new before a change out.
bruce
Also the metal will show a bad air filter (SI) or anti freeze leakage (NA,BR,MO)
Insolubles will show sludge formation
Oxidation or nitration numbers will also show potential sludge and varnish precursors.
Viscosity will show oil breakdown as in shearing to lower vis grade or fuel dilution or even with high soot or oxidation it will show oil thickening
basicly any change from the new oil profile can be noted and when something is out of range its time for a oil change out or some engine maintnence.
That is why I like also a baseline VOA of the exact oil used since ALL published specs are a "typical or average" data point and
most likley are not the exact PPM numbers in your current oil from the bottle. Sometimes silicone AF maybe used in Motor oils and the amount does vary from batch to batch if you have a batch with a "high" number the UOA will flag SI and say you have a air filter leak when you do not.
As a basic bench mark to oil changes TBN retention is as good as any mark to make a change out decision I like TBN to retain at least 20% of new before a change out.
bruce
Both a science and an art, only took me 30 years to figure it out, good luck.
In the meantime , give us a try.
Getting an analysis result with poor interpretation is like having a spouse with no reasonably satisfactory interpersonal relations.
Terry
www.dysonanalysis.com
In the meantime , give us a try.
Getting an analysis result with poor interpretation is like having a spouse with no reasonably satisfactory interpersonal relations.
Terry
www.dysonanalysis.com
Blackstone Labs has some info on how to interpret a UOA:
http://www.blackstone-labs.com/gasoline_diesel_report_expl.html
More info on their site if you click around to different pages.
http://www.blackstone-labs.com/gasoline_diesel_report_expl.html
More info on their site if you click around to different pages.
Terry,
Are you saying FIGURING OUT a UOA is like trying to understand women ?
It is a Great analogy Terry
Care to get into what that "aspect" might entail?
If Terry had spent the last 30 years trying to figure out women, he would either be filthy rich because he suceeded or completely empty handed because he failed.quote:
Originally posted by Bill:
Terry,
Are you saying FIGURING OUT a UOA is like trying to understand women ?
The sad part is that many of the users of BITOG would still be his customers even if he did specialize in the analysis of women.
medic, that statement is just WRONG!!!!
Well Bill, I am glad that comment made you laugh!
I was actually focusing on the expectations that we all have when we have a great relationship and finding out the other lover isn,t as into that aspect we would have wanted.
Poorly intepreted oil analysis is exactly like that, leaves you wanting !
I was actually focusing on the expectations that we all have when we have a great relationship and finding out the other lover isn,t as into that aspect we would have wanted.
Poorly intepreted oil analysis is exactly like that, leaves you wanting !
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