dickytim: Did you go to the mechanic and ask him to fix the tensioner issue by any chance? If so my may have to suffer through this as he will have done what he was instructed to do.
If you told him to fix the noise and he replaced parts that didn't need replacing ask him why and if he test drove the car sufficiently after to determine it was fixed.
I somehow have a feeling we are talking about the latter here.
We told them there was a noise coming from the vicinity and we think it could be the tensioner. He carried out his own testing and 'confirmed' this ... so yea, the latter.
I don't think they even took it for a test drive afterwards because when i arrived to pick it up, they were only just backing it out of the mechanics bay.