hello mate you need really to stop driving it,coz the chain will skip cog teeth causing costly damage. your lower guide,tensioner might be at fault, etc.87k is not that high,its just one of those dreaded things. it could of been 87k of tear assing about.history dont show how fast and mad the car was driven.and chains stretch but not to the extent they flap about.but i know of 2 vr's which had chains done at the stealer @49k and the other @66k.and a full engine flush to cure a mechanical rattle what B*****ks.ill be attempting mine soon.we've all got to do it one day.