Questions and Answers

BMW 535I Rolling Idle Q. Hi, I have owned my 1987 535i for about ten years now and it has always had this strange rolling idle when standing still (otherwise its smooth as silk). I have been told that it has an aggressive cam that causes it to do what it does. Sometimes it shakes allot and some days it feels somewhat smoother (sounds strange but it does behave that way).

Can you shed some light on this as to whether that cam is the real cause or not? I love all the other features of the car like the handling and braking and power under foot but this one aspect of the experience has always bugged me. There does not seem to be any way of controlling the idle in a manual fashion, like in the old carburetor days.Your take on this would be much appreciated.

Thanks,
Dan

A. BMW has always used an aggressive cam in their engines. As a consequence the engine will have a little rougher than normal idle. You can't get high end performance without losing some low end performance. This is what we call the nature of the beast.