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