Tim, on the 20v 5 cylinder engine, the oil filter screws onto the bottom of
the engine, so the oil cannot drain out of it. (This is also very nice when
one changes the oil and filter.)
I saw farther in your post you have the 10v and 20v engines. Is the oil
filter placement different on these?
Anyway, I seem to remember something in my owner's manual about ticking
noise from the hydraulic lifters. It says that it is acceptable for the
first few minutes in a cold engine, provided the engine is not run faster
than about about 3000rpm. Mine has never "ticked" for more than ten
seconds, even after sitting for over a month.
And back to the original post, if anybody told me 15w40 oil damaged a 9 year
old engine, I would be suspicious of anything else that mechanic had to say.
That is exactly what weight of oil I would choose in my car if I were to run
it hard on the autobahn.