Hi I have recently noticed my 406 (2.0 HDi, yr 2002, 90bhp) making a deep "moaning" sound. My first suspicions was a warn drivebelt and so I replaced this. The problem was not solved. Upon taking the car to the garage they have investigated and told me that the bearings have warn in the belt tensioner thus causing the belt to vibrate which is the noise I hear. Quote is 5 hours labour and £35 + VAT for a new tensioner. Has anyone ever replaced the tensioner themselves? Haynes does not seem to give any instructions on how to do this. TIA Ol