Where have we seen this one before? Another shop had done a timing chain replacement on this car about 18 months ago, but it appears that not everything may not have been done up to snuff. On disassembly the technician also found a defective/seized engine vacuum pump, which caused the chain to bunch up, and break the upper tensioner guide. A part of the broken guide fell down into the front of the engine, getting caught between the crankshaft sprocket and timing chain, locking up the engine, knocking the camshaft timing out of order, and leading to bent engine valves. The result is the same as tensioner failure, and upper engine tear down, inspection and rebuild was needed.
Be certain, if your Mini has noise from the timing chain area, that the complete update kit be installed, with the latest in factory parts, the service parts for this update are quite inexpensive, it’s the labor on this job that is the largest expense.