Noticed when I removed the air filter that there is a very small amount of engine oil in the bottom of the air cleaner assembly. I removed the hose for the crank case vent and found film of oil inside the hose. When the mower sets for a week or longer I see a small cloud of blue smoke out of the muffler when I start it. I'm guessing the reed valve in the vent is not holding? The mower was new last year and has 160hrs now. It is a model SS3225 with the "Toro" made single cylinder engine. The oil is not over full and was changed at 85 hours. I'm using Mobile One Full Synthetic 10W-30 motor oil. Every time this past summer when I checked the oil it has been right on the full line.