Chuck Tribolet wrote:
There shouldn't be ANY sheen at all.

The lower unit can be pressure tested. Be sure to test it at both
low (like 1 PSI) and higher pressures per the service manual.

ok, dumb question. how would I go about doing that?

if I do the test, what would the results imply is causing it?

One of my whaler buddies had an engine that wouldn't leak at the
pressure speced by the manual, but would leak at low pressure,
and leak in the water.

I know that our older engine leaks a bit, and there's always crap
coming out of it when we take it out of the water, but we're never that
low on lower unit lube (or other fluids).

If all else fails, I might just take it to someone someday to have them
look at it.