Chain tensioner failure is a common problem for the Generation 2 MINI R56 Cooper S, it is characterised by a loud rattle noise referred to as the “Death Rattle”. This “Death Rattle” is particularly prominent when you first start your car on a cold morning. As the engine oil begins to circulate around the engine and the oil pressure builds up the oil acts as a damper and reduces the noise.
One of the possible causes of this “death Rattle” is when the timing chain support rail looses tension. When the chain is not under the correct amount of tension it is free to move around and rattle against the chain guides. This particular rail is made of plastic which over time and exposure to heat can deteriorate and eventually break.
Ignoring this “Death Rattle” could have detrimental effects on the complete timing system and worst case scenario the engine.