We have found about 1/2 ounce of oil in the pan and another 1/2 ounce in the upper bildge (area below the companionway lader) after we have run the motor. We have cleaned the bildge and pan after each of the three motoring events but the oil is back the next time we come to the boat. We cannot locate any area that it is coming from. Since the oil was changed at the beginning of the season, there has been no change in the oil level. The oil pressure is within normal limits and exhaust smoke is normal. It is a Universal M25. Does anyone have any ideas where the oil could be coming from?