On May 23, 8:09 am, "Robert M. Gary" wrote:
I have a mid time (1000 SFNEW) IO-360 Lycoming engine.
Recently oil consumption has increased from about 1 quart/10 hours to
about 1 quart/ 5 hours. For a long time we've collected oil on the
bottom #1 plug but it seems like its worse now.



Robert,
Oil is cheap compared to finding the problem, however if I was
wearing your sneakers.........
I'd say you have a broken oil control ring on that cylinder. It will
still show good compression, but just burns more oil. I would pull
that jug and inspect it.
option 1 $: put a new oil control ring and go fly
option 2 $$: hone it and re-ring the piston, If the piston is messed
up from the broken ring, replace it as well.
option 3 $$$$: bebuild that jug.

In regards to the piston plug idea. all you know is that you have had
some alumimun in your oil, and now some iron, and a lab "thinks" it
might be a piston plug.
however It might be an oil control ring eating it's ring grove. It
might be a small bur in your oil pump eating the oil pump housing. it
might be one of many things.