the packing used in between the oil chamber and the block is called "Chamber Packing or gasket".
The issue with ur car is the packing that is used between the head and the block. it keeps the oil and water separate and is called " head Gaskit".
Gaskit means
"A gasket is a mechanical seal which fills the space between two or more mating surfaces, generally to prevent leakage from or into the joined objects while under compression. Gaskets allow for "less-than-perfect" mating surfaces on machine parts where they can fill irregularities."
if there is foam in radiator cap, then do check the oil cap. if there is foam, then the head gasket needs to be replaced.