I OWN A 1984 BUICK T-TYPE. I WAS CHECKING MY AIR FILTER AND NOTICED ABOUT HALF AN INCH OF OIL IN THE HOUSING. IF THERE IS ANYONE WHO KNOWS WHAT THIS PROBLEM IS AND HOW IT CAN BE REPAIRED PLEASE LET ME KNOW, IT WOULD BE GREATLY APPRECIATED.
Oil is blowing up the oil filler tube and into your intake. You are pressurizing your crankcase somehow. It could be from a bad PCV valve or bad rings, or maybe bad valve seals. Start with a new pcv valve, then get a compression test.