On Tue, 2 Nov 2004 16:36:16 -0600, "Gary Wilcox"
wrote:

What is the likely source of this aluminum? The mechanic suggested that I
fly for 10 hours and change the oil again to see if the problem goes away.

Be careful about flying with visible metal in the filter. I had a
similar problem with my O360. Metal in the filter and I grounded the
airplane. My AP said nearly the same thing as yours, but suggested
that we look in the finger screen that is right before the oil pump
first. Pulled that and there were thumbnail sized pieces of Al in it.
So many large chunks that it was nearly plugged its whole length
(~4"). We started pulling jugs and found that the back bosses of one
piston (that provide support for the wrist pin) were nearly all broken
out! I hate to think what might have happened if I did fly a few more
hours....

My suggestion is to check the screen (not very hard to do) before you
fly.


Anyone seen a situation where aluminum in the oil was a one time thing?


Not very likely. The piston/wrist pin plugs are about all there is to
make Al.

Good Luck,
Jerry