On Mon, 29 Jan 2007 13:49:26 -0600, "Dan Luke"
wrote:


wrote:

Definitely have an A&P borescope that engine. Broken ring maybe.

Talked to my mechanic this morning. He said not to worry; the dirty oil is
from the oil cooler and its plumbing, which don't get drained when the oil is
changed.

He said I would have noticed this before if I had ever checked it two hours
after a change. Since I check the oil before every flight, it seems I would
have noticed the oil's turning black this soon before.

Should I pay to have the cylinders 'scoped?

Your mechanic's comment sounds unrealistic. I have a hard time
believing the 1/2 quart in the cooler & lines could add enough
coloration to the 7-8 quarts of new/clean oil.

Further, I don't notice my oil turning black until many hours after
the change. (Lyc O-360 using Aeroshell 15W50), and I never flush the
cooler during a change.

Is your oil a dark black? Or just a tinge of coloration?