Can AOS leak oil?

[sasha055]

I've been fighting an oil leak fore more than a year.
It has all the classic symptoms of Oil filler tube leak. There's oil on top of the engine, and it leaks a couple of drops only if I push the engine from 2K RPM to redline.
If I drive slow and smooth no oil is dripping.

I changed oil filler tube 2 times and it didn't help, so last week I wrapped my oil filler tube with plastic and went for a long drive... the plastic was oily on the outside, my only other suspect is AOS
It all started about 6 month after I changed my AOS so either I screwed up installation or maybe AOS went bad that fast..

Can AOS leak oil? if yes were would it come from?

Thanks
Sasha