[Walt Fricke]

My experience is that there is always some air you can hear when you put a tube in your ear and stick it down into the inside of the case, like via the oil breather. As long as the actual leakdowns are good, I don't think anyone worries about that. If you had bad numbers, but no bubbles around the intake and exhaust valves (spray soapy water or Windex into the ports with an engine with the intake and exhaust off), that would be different.