My 740iL will start puffing oil smoke if you leave it sitting at idle. I have replaced the idle speed motor and checked operation of throttle position sensor. There is a noticeable vacuum on the crankcase - i.e. pull the dipstick out and you can detect a sound and airflow. How much of this is typical? I am at a loss other than oil ring problem or valve stem oil seals maybe? the compression tested good 140 and up on all cylinders. Could the EML be sending the wrong signal to idle control and not allowing enough air past the throttle plate, forcing the engine to pull it from elsewhere? Off idle the car runs STRONG. Any suggestions?