Oil passes to the admission multiple

Hello, in what anomalous situation the oil can go to the admission multiple in an Opel Vectra in 98, multiveralvular?

Some oil vapor is always normal in the admission that comes from the recirculation of the carter gases, which you do not tell us if it is diesel (with turbo) or gasoline. If it is Diesel with Turbo, the problem of an excess of oil in the admission can come due to a wear of the turbo axis. Excessive engine wear (cylinder-piston) can make a lot of pressure in the oil carter and "blow" too much, all this steam into the admission, also a problem in the vapor reaspiration system (PCV valve open for dirt).