2004 signum cdti whistling noise??

i own a 2004 signum 150 cdti.i had all the problems with egr etc,luckily myself and a friend was able to carry out removing the head,cleaning everything up with new rocker arms etc.removed the swirl flaps,blanked them off with correct blanking bungs,put it all together,now i have a whistling noise that kicks in at about 3tho revs when sat still,and about 16tho revs when driving..its not any pipes split,the turbo is fine,and the noise is very much near the egr??? any help will be appreciated..