I recently cleaned out my throttle body, and then took it apart again after just a couple weeks to chase down a high idle problem (which turned out to be a misadjusted throttle position switch). I also have recently cleaned out the flame trap and associated plumbing, and the IAC valve.

When I got the throttle body off the second time, I noticed that on the manifold side of the TB there was an oily film on the inside surfaces. On the intake (AMM) side of the throttle plate it was dry. It wasn't a dirty or dark film of oil, it looked like clean engine oil (I recently changed the oil), but I suppose it could have been something else. Could it have something to do with the IAC valve being out of commission due to the misadjusted TPS? I was expecting the TB to be dry throughout, especially since I just cleaned it. Come to think of it, I have never opened up a throttle body so soon after having cleaned it. What could be the explanation for this oiliness on the one side of the TB? Is this normal or is it a problem?