Blown head gasket and/or cracked head.
You possibly have a leak in the cylinder head gasket.You possibly have a leak in the head gasket.
A leak some where in the system, such as a bad head gasket, a cracked head, a leak from the radiator, a leak from the water pump.
It is either an intake gasket leak or a head gasket.
rocker cover gasket or valve inspection gasket leaking
Head or head gasket leak
If its coming from under the chrome cylinder head cover, its the head cover gasket.
A head gasket leak. I had one, its not fun
If it is leaking from a bad head gasket, it is because of a bad head gasket. If it is leaking from a bad intake manifold gasket, it is because of a bad intake manifold gasket.
Any internal coolant leak can cause a milky residue in the valve cover. Head gasket, intake gasket, cracked/warped head, cracked intake are possible causes.
If you ran your car too hot you may have warped the head which would cause your head gasket to leak water or oil. You need also to hone the heads to make them flat again.
It requires replacing the head gasket.