Quick Engine / Throttle Question

Completely normal with the gen2, Bob. Many a PCer who has cleaned their own throttle body and posted about it has noted it. Although PCV is the seemingly obvious candidate for cause, it's not clear that engine wear is. You can find examples of young, low-mileage Prii right along side "mature" cars like yours and mine. It's likely they do this from birth. The amount of oil you describe is exactly what I see in my 07 w/145k. Some here like to mop it out of there but I don't bother. It's a little perplexing but a non-issue.

 

I "mopped" out the intake manifold of my 2008 twice using a dangerous but successful method you can find if you want in my previous postings. The fluid was more than just engine oil, which I suspect arrived there via the PCV. Some portion of it was a clear fluid most likely accumulating in the manifold due to the Atkinson cycle. It had a slight odor of gasoline but was not as volatile. I felt better getting it out of there but it probably makes no difference if you leave it there.