vent housing is rubbing on my 750 bmw auxillary fan

Maybe someone has experienced this?

When I shut the hood bad noise

I had a bad aux fan and went to E38.org and was able to remove bumber and change fan. http://www.bimmerboard.com/forums/posts/822560

I put it all back together and when I shut the Hood the housing over Aux Fan now rubs on fan and it sounds like a airplane.

I have had it apart twice and can not get the plastic housing installed over the fan to stop rubbing once hood is closed. This housing help direct air on to the condenser.

I purchased a aftermarket hower I do not think the fan is the problem the hood is pushing the housing in.