The change interval for an M47R timing chain is 250,000 miles, I've yet to hear of anyone doing that........for instance Mike Noc, and a couple of taxi drivers where their mileage is over double that.
However timing chain auto tensioners are known weak points on Mini, and Vauxhall, mainly due to the extended oil change intervals.
Normally speaking if there is any hint of rattle at start up, then expect to have to change it.
If she hasn't bought the car yet, take time to check it from stone cold, preferably after an overnight period.
Brian
