Sorry for the lateness of this reply; I thought I had answered it from my iPad about a week ago.
I would not worry much about the moisture you’re seeing. Moisture is a by product of the combustion process and since our engines are open to local atmospheric conditions–though the breather tube–moisture in the air does condense on the inner surfaces of the engine.
The presence of moisture is the primary reason running an engine on the ground is a very poor practice since it never completely gets all the engine parts and the oil up to full operating temperature. Flying to “cook” out the moisture or using an engine dehydrator when not flying are the only ways to to combat the effects of the moisture.
Local atmospheric conditions will increase the likelihood of moisture formation.
I advise you to continue to monitor the situation; unless you’re seeing variations in other engine parameters such as increased oil usage I believe you good to keep flying.
