If you suspect the chains need changing the noise will be a loose rattle sound,with the bonnet up and engine running the sound looking at your engine will be to your right,at the back of the engine upper you will see a large bolt that is one of the tensioner ajusters,the sound will mostly becoming from this area and to the right lower side, do not be tempted to have this tightened up to stop chain rattle as this could stretch an already stretched chain,and snap it,then your in big big £ land. I have had my 97 chains done on the 13th aug 10. Euro carparts for entire parts to do the job £164 L