What engine is this?
Oil
pressure is a different switch, if we are talking 3.0.
There is an oil pressure "switch" (#12):
RealOEM.com - Online BMW Parts Catalog
and an oil level "sender" (#14):
RealOEM.com - Online BMW Parts Catalog
If you are leaking, CCV can lead to oil coming out of places it should not...again on a 3.0.