Do these engines have Hydraulic chain tensioners ? slotted cam gears ? I'm not up with Diesel engines only petrol based.
I've just spoken to Nissan who have gone through their records and determined that my car has part number 13028-EB300 in it. This would seem to indicate that my timing chain is potentially in danger of failing.
I think it's going to go have a night at the doctors so they can listen to it at cold start.