This happened to me last winter and I was out of town. I had no choice but to get it to a shop. approx. $400 at an independant shop.

One month later, I was out of town again and the same thing happened. $800 this time. New OSV, valve cover gaskets, and vent hoses. The OSV "freeze up" issue seems to happen whether or not the hoses and OSV are new. From my experience it seems like a design problem related to cold weather.

The newer X5's might have an insulator for the OSV hoses. I read about it in the forum but I was never able to track down a part number. I've asked my dealer about it, and they claim that it doesn't exist.