my 06 530xi with 109k has been experiencing almost misfire like symptoms(almost hiccuping) in 3-6 under load(between 2500-4000RPMS). This car had ZERO codes as well. I brought it to a few mechanics with the idea of it being in the ignition system somewhere, again it seemed just like a misfire! After three mechanics Nobody could pinpoint this problem. The last mechanic i brought it to was a bmw mechanic so i had confidence. He told me off the bat he did not think it was in the drivetrain because it was not happening in first or second gear only third and up. After two days of him looking at it he could not figure it out. He swapped the coils and all that sort of stuff and told me to bring it to somewhere with a "computer"?. So I had no other options except to bring it to BMW. They let me know after further diagnosing it was the transfer case and it was $3000.... yeah ok... So i contacted a local transmission shop and explained him this story. He said he could possibly service it without replacing it. I am still waiting for an answer from the guy but i'm just extremely curious if anyone else has seen this issue? Thank you!