2006 BMW 525xi when at idle it pulsates around less than 1000 rpm on 2006 BMW 525xi

I have new crank thing. Also I have replaced all spark plugs and oxygen sensors. Replaced mass air flow sensors. it has to be something with air intake something small I'm thinking. Please help

2 answers
Try cleaning the IAC motor or valve. Be sure to check hoses connected to it for cracks and or dry rot. Here is the general procedure for your vechicle: http://www.ehow.com/how_2301261_clean-air-control-motor-valve.html
I'm thinking....BMW dealer........less expensive in the long run.