That what happens when u get a cracked block or a cracked head, as engine heats up the crack opens and puts combustion pressure into the cooling system and pushes coolant out of the rad, Not alway do u get coolant in oil as u suspect. If plugs were pushed out I would suspect u have a crack somewhere, combustion gas test should be preformed on cooling system. Won't tell u where crack is but will tell u if u have combustion gas in cooling system, ie crack or blown head gasket. Bad news.
