This is common, the hose with the hole goes to the oil separator,and the hose that connects the valve covers will get worse if not replaced. And there is a third hose that is under the oil separator , this one is about six inches long. You should replace all three. If not replaced they will lean out your fuel mixture, thus gas mileage out the window and generate fault codes "Bank1 and Bank2 too lean"....or MAS fault
For some reason these hoses can`t take the heat and oil, they get all gummy and collaspe or rip apart. They are not expensive, but the short hose, Hummm is a bear to change, the Fire wall must be lifted to get to it. And if you notice a hint of blue smoke at the exhaust, replacing the oil separator would be a good idea.
Hope this helps..

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1979 320i/6 w/ m20 engine /5 speed
2001 X5 4.4i w/Sports Package
1998 M3 w/HR springs / Bilstein Sport struts
1994 735i Black w/black interior (sold)
1986 528e Black w/ black interior (sold)
1985 325e 4dr (sold)