I hope you're not talking about a 540, from what I've heard it's a huge pain in the ass. I had a friend who was quoted $4g by a dealer to fix it. I know, I know, it's the stealership, but our local german mechanic wouldn't even touch it, so the dealer was a last resort.
Edit: Oopsie, I'm a liar, his was an e34. Still, I hope it's a 6 cyl.