I have a 2004 E60 530d with only 43Kmiles on it. The car is in good condition and has a full service history. I have very recently changed the oil breather from the original foam type to the newer plastic type. The car is now producing very noticeable blue exhaust fumes for about 3-4 seconds when starting from cold. Have i made an error in changing the oil breather or is something else wrong? Any thoughts would be much appreciated.