Are you saying the first ccv plate was faulty, and you have now replaced it with a second one? Did the whistle/howl go away with the new one?
The reason I ask is, I just installed a new (ccv, pvc, intake manifold plate) on an m60 today. Along with all the mainfold gaskets and some other repairs. Now it whistles/howls at idle. When I pull the dipstick, the whistle stops. Other posts I've read
indicate this is due to faulty (ccv, pvc, intake manifold plate), but I just put a new one on! Perhaps I have a faulty one too.