hi firstly chains last a long long time maybe up to 150k miles, on this particular engine as with the older nissans 94 onward there is a oil filled tensioner, now what this means is when you start your engine the oil pump pumps oil into the tensioners which causes them to inflate as it were, therefore they push into the chain and take up the slack wich makes it run smooth and quiet, but you will find if the cars oil and filter hasnt been changed then they gunk up and dont take up the slack therefore the chain rattles, i would recommend getting some engine flush pour it into your engine with the old oil still in there run the engine till its hot this will hopefully get the gunk out drain the oil, replace filter with genuine nissan filter and correct oil, start engine and hey presto no more rattles from your nissan timing chain, hope this is helpful, e mail jdoggydog0601@hotmail.com if you need any further info mate
jason key, April 2006
