To test the system, remove the oil fill cap, you put a large piece of plastic, like a trash bag or
plastic glove over the oil fill opening on the valve cover. The plastic should get sucked in
slightly. If it pushes out, you have a problem. If the hoses are original, then yes you should
replace, they get old and brittle, crack and leak. Mayo in your lines if from the synthetic oil
mixing with water condensation. I suspect you only drive short distances in the cold, which
would increase the Mayo. Take the car out on a long trip 30 minutes or more to properly heat
up the car and burn off the water condensation in the oil and CCV lines at least once a
week.