FIXED-You can read the whole thread or long story short it was a Faulty camchain tensioner (£30 part and 30min easy DIY to fit) causing the rattle. And a faulty set of VANOS solenoids causing the power loss (bit more expensive for the parts but again about 30mins easy DIY fitting). Read on for the details and see the youtube videos for my syptoms and a comparason of the old and new style tensioners
Part 7&8 are in the kit for the tensioner here http://www.realoem.com/bmw/showparts...89&hg=11&fg=25
Be sure to change o-rings 2 and 3 with the vanos valves (part 1) here http://www.realoem.com/bmw/showparts...96&hg=11&fg=15
And the bad news is you need 2 of them unless your lucky enough to know which one is faulty...I did find this video AFTER i replaced both of mine though which could help someone.