Is it normal for the valve train to be noisy (knocking sound) in the S until the motor warms up? When the motor warms up, all I can hear are the injectors.
It's not the death rattle. It's just a noisy camshaft.
My daughter's MC sounds like a Rolls Royce compared to my MCS.

 

The vacum pumps have like a knocking noise to them, but its normal and i wouldnt worry about it. If its the real bad timing chain noise i would take it to your mini dealer for the fix.

 

Definetly have your dealer check it out. There has been updates on the timing chain tensioner and that's likely the problem.