Small amount of oil in the intake tube ok? Or do I have a PCV problem?

[table5511]

So I took out my drop-in K&N filter after 20k miles of use, mainly to investigate pinging/pre-detonation during warmup under moderate accelleration, only when needle has not reached normal temp. After that, pinging is mostly gone. (when the windows are down and i'm going slow, about 25mph, and tap the accellerator, I still hear a tiny bit of initial cackling, but it's mainly only during warmup).
The upper aircleaner housing cover was clean. No oil, no dirt. MAF sensor looks fine, no oil or dirt on it either.

What I did discover was a small amount of oil coming out of the breather hose and into the intake tube.

For those of you who know anything about motors, would you consider this a normal amount? My motor only has 55k miles.
I don't know if this is the cause of my pinging under warmup or not. I've got 5k miles left on the powertrain warranty.

I put a new Ford air filter in there just to see if for some reason the change in airflow is the cause of the pinging.

I have read on a couple other forums where a K&N drop-in filter was the sole cause of pinging, and that the computer just doesn't change the air/fuel ratio when more air is entering due to the K&N filter.

But anyhow, I wonder if this amount of oil is normal or if I should bring it in right away?

(the long white streak is just the manufacturing of the rubber...its not any stain or anything)

 

[jk240sx]

That honestly doesn't look like a lot of oil. it looks varnished like it's been depositing over a period of time. I'd pull the tube out and off and hit it with carb cleaner and wipe everything down. Then keep an eye on it.

As far as the pinging goes, do you use winter blend there? We have it here and it causes slight ping in both my vehicles. When the stations switch to summer blend, it goes completely away.

 

[table5511]

Yeah they do, and I use shell only to avoid cheap chemical gas from cheap gas stations. But again, it is really just during warmup, and I have noticed it during the summer too. We will see if the OEM filter makes a difference.