The Timing Chain and related components are not your 'typical' maintenance item. However, the early N14 engine had an occasional issue with the Timing Chain Tensioner causing a condition referred to as the 'cold start rattle'. You can find more details about this condition in our article Mini Cooper Cold Start Rattle.
The Timing Chain and related components are typically replaced during an engine overhaul, or if the timing chain 'stretches' beyond acceptable limits. When this happens, the timing chain will start to make 'rattling' sounds.

Below is an application guide on where to find the appropriate MINI Factory replacement parts for your MINI.


Mini Cooper Timing Chain Factory Replacement Application Guide:

 

"occasional". That's funny.