Why do I have blowby coming out of my valve cover? on 1998 Jaguar XJ8

I have a 1998 Jaguar xj8 and blowby is coming out of the valve cover and going into my mass airflow sensor, going into the intake and fouling out my plugs.

1 answer
That has a 4.0L engine. It may have a broken piston ring! Have a compression test, cylinder leakage test done. On removing the spark plugs see if a plug is oil fouled, have the garage use a boreascope to examine the cylinders for scoring or damage.