My car is emitting white smoke while idling. Does it need a valve stem replacement?
White smoke while idling is normally reason to believe that your BMW may need the valve stems replaced, however this can also be the sign of bad Crankcase Ventilation (CCV) gaskets. On top of those possibilities, there are many things that can cause white smoke at idling, therefore I recommend enlisting the assistance of a certified mechanic, such as one from YourMechanic, to come by and diagnose your BMW in person. They will have the knowledge needed to quickly identify the cause of the white smoke. They will also have the tools and experience necessary to assist with the repairs needed to keep your BMW from polluting.