thoughts on UOA... wear# = fn(filter efficiency)?

[08sienna]

Wouldn't wear numbers depend on the filter efficiency?
Engine wear particles are supposed to be filtered and stored in the filter -- therefore, numbers shown in UOA only count the metal particles smaller than whatever the pore size the filter is spec'ed..
If so, lower wear #'s could be nothing but an indication of higher filter efficiency...

 

[Leo]

Possibly but if I recall correctly, used oil analysis look at wear particles smaller than what most filters can catch. I cant recall the exact particles size exactly...

EDIT - it seems that most equipment cannot detect particles larger than 5-10 microns, which is smaller than most mainstream oil filters can remove efficiently.

 

[INDYMAC]

I have had similar concerns about used oil analysis. But I feel pretty confident after checking the used oil filter and used oil drain pan for visible signs of metal debris and don't see any, that the oil analysis is fairly accurate. If you find debris evident in the filter or drain pan, then further investigation and analysis/interpretation is required.

 

[LargeCarManX2]

Good question....

Add the bypass filter to this thought!

 

[Jim Allen]

used oil analysis look at particles <5um. An oil filter may catch some of them but it takes a very efficient bypass filter to dramatically change the metals in a used oil analysis. In fact, when operating a bypass, it will skew the readings so that if you are trending, it will throw all that off.

 

[bluestream]

Anything that is small enough to pass through the oil filter will cause no extra wear. Popular myth around here.

 

[ARCOgraphite]

Any abrasive particle larger than the running clearance on the cam bearings, rod, mains etc will cause wear. This includes 7-15uM which are usally multipass at

 

[LargeCarManX2]

I know that soot reaks havic on oil...what size are soot particles?

 

[ltslimjim]

The only real advantage most of us could hope for would to be having bypass system installed and get all tricked out with 1 year intervals on the best juices + filter combos. Did I mention oils?