Hey Steve! You? a BMW?
Hey if its got less than 70K or a million miles or so miles, it probably wont be the timing chain. Its fairly easy to diagnose those though- even though they are all less slack than OCJ's
It will show up as a timing mark with ants in the pants. It wont sit still no matter what. And it can sound like a bunch o rocks in the front cover.
It sounds like its got a intake vacuum leak someplace. Will be a little devilish to chase down but no big deal.
Have you even seen the thing close up?