My 216 also seems to get louder when the engine is warm. Fairly quiet at startup when the 20w-50 oil is cold. Oil pressure is about 30psi at initial startup but eventually drops to 15psi at speed as it warms up. Idles at 7-8psi.
I don't think less oil is being sent to the top end. I think the oil just thins out as it warms up and thus the valve clatter gets louder.
What weight oil do you use, Thomaslb?
