"Last year MINI finally solved
the dreaded cold start issue that afflicted the R56 Cooper S. Or so they thought. As it turned out, while the issue was eliminated in some cars but only alleviated in others. So MINI went back to the drawing board and looked the issue with fresh eyes. After further research they believe they have finally (and definitively) solved the issue for all cars with a modified timing chain. Specifically they’ve made the chain very slightly longer which has eliminated the chatter that was known as the “death rattle”.
The new components should come online at the Oxford Plant in time for March builds. For those with older R56s still afflicted with the issue, MINI will be offering an official fix for your car. Of course keep in mind that this will be a case by case process and you should work through your dealer."
MotoringFile » Archive » MINI Solves R55/R56/R57 MCS Cold Start Problem (Again)