I don't know if they were changed. This thread notes that the colour changed to signify the new version, but you should confirm that on realoem with part numbers.

http://www.xoutpost.com/bmw-sav-foru...your-cost.html

Valve stem seals are not new technology. In my experience from other engines, the problem would likely be seal composition (hardening with age) or oil pooling on top of them. The problem is worse with worn guides as the valve stem moves and loosens the seal, but the fixes reported don't talk about guide replacement so I would suspect they are fine in most cases.

I haven't done a BMW but I have replaced seals on a Ford V8 I owned by making a tool up. I used shop air through a fitting in the spark plug hole to hold the valves in place and changed seals without removing the heads. That appears to be what people are starting to do on this engine now.

I think the whole oil change interval discussion is nothing to do with it.

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