The old stock filter was old and dirty and has been replaced.

In the middle area of the filter it was blackened (much dirtier then the rest).

didnt think much of it, replaced it, and the new one is like that almost straight away.

Why would this be? Normal?

Cheers.

Mark.

 

Could get a pic to make it clearer... no one had anything like this?

 

Oil vapours are circulated through the breather/boost pipes. That can cause it sometimes. It's done because its illegal for car manufacturers to vent these vapours to the atmosphere at production. You can either fit a breather filter or an oil catch tank. The tank is the more ozone freindly option, but it costs more. 40 - 50 quid compared to a 5 - 10 pound filter.
But of course if you make these mods, the oil residue is already in the system now, so its best to clean them out then fit the tank/filter for maxium results.
Search for breather, there is plenty on the subject.