Tony wrote:
>I used Blackstone in the past. What disturbs me is that I sent in the oil
>from my Elise. At 18K. After the 18K oil change I stored my car for the
>winter. Did not start it or run it. When I started to get ready for spring,
>as my warranty was running out, I checked the cams for the dreaded early
>wear issue. And I had it. My cams were visibly worn and Blackstone did not
>show anything unusual in the sample I sent them 5 months earlier. Keep in
>mind that I did not drive the car for those 5 months.
>
>Now I am not blasting them, or anything like that. I am just telling you
>what transpired. As I recall the only thing unusual was a high silica and as
>I recall a little high on the nickel. Now I don't know what level triggers a
>concern and how they interpret their levels. All I can say is the I had an
>on going issue and they did not pick up on it.
Perhaps the wear occurred in the prior oil change cycle and thus
didn't get picked up in that UOA?
On my TDI, I had a lifter fail and snap the timing belt last fall
and had to recondition the head. On my next UOA, I could see slightly
elevated iron and copper as the new lifters bedded into the old cam. By
the next UOA, those levels were down to normal.
On their reports you can compare the "universal averages" column
(averages for that particular engine type) with the "unit averages"
(averages for your engine). Based on the comments on my 12 reports, they
look for numbers outside the range for either your engine or that engine
family overall. Maybe those engines tend to have high iron numbers because
of the cam issue and thus the iron number didn't trigger any comments from
them. Just guessing.
In any case, a UOA is not the be all and end all of engine
diagnosing. It is a tool that helps evaluate oil performance and can give
some general idea of engine health.
I do UOA on each oil change because this is my work car. A UOA
report may give me advance warning of an issue - high water or antifreeze
may indicate a failing head gasket. High wear metals indicate different
areas of concern - chromium in likely from the rings, iron from cams or
rods, lead\tin\copper from bearings. High silica is generally from dirt
getting past the air filter.
Todd
Seattle,WA
'86 GTI, Red of course. (exciting racey car) 273,000 miles
'01 Golf TDI, silver. (new work car) 290,000 miles
'87 Golf, Polar Silver. (retired work car) 654,000 miles <- Gone to a new
home :(
http://www.pureluckdesign.com <-Ferrari & VW stuff
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