[RayLivingston]

For the last 6 months or so, my '07 335i has had an odd problem - When fully up to operating temperature, driving on surface streets on a hot day, the idle speed varies rhytmically. It mostly idles at 600 RPM, but about every 5 seconds, it kicks up to 700 RPM for about a second, then drops back down to 600 RPM. It does this continuously. It idles fine when cold. If I turn OFF the "snowflake" switch, to disable the A/C, the problem goes away entirely. The A/C is working perfectly, putting out lots of ice cold air.

Regards,
Ray L.