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

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.