Ross

I have a 172M with an O320E2D @1700 hrs TTSN with the same oil filter
system that likewise is cold blooded. My guess is that ours has very
little blowby as the oil also stays clean for many hours after a
change. It has been run mostly on MoGas, so the contamination load on
the oil is low. Does your oil stay clean unusually long too?

Have you tried covering part or all of the oil cooler?

Ours does not have a Vernatherm element installed in the oil filter
adapter - only a plug. Does yours?

My guess is you have a very good break-in. I don't think it is
something to worry about.

The justification for having the oil run above 180 degF though, is
that the dew point of the combustion products is about 180 degF.