[GrahamBrown1]

You would be better posting this a separate post to get a greater response. What you need to do is remove the auxiliary belt first and check the tensioner idler and alternator clutch. if these are ok then run the car to check the cambelt area. If the noise is still present then you know where to focus. This is not a hard job if your handy with the spanners and a member on here has a video of exactly what to do. has your cambelt been changed? if not its over due as the interval is 10 years or 108,000 if I remember correctly. You also need to change the above mentioned parts as its these that cause cambelt failures not the cambelt breaking itself. Also Volvo genuine parts is the only way to go when dealing with this area.