Mazda 626 Tensioners - merlin
My Mazda 626 diesel is due it's 108k service which includes the cambelt change. Talking to an independent garage today they suggested that it might need the tensioners changed even though they are not a service item. The tensioners will cost an extra £120 on top of the £430 they want for the service. So what sort of life should I get out of the tensioners before they need changing?

The local Mazda garage want £580 for the same service (price excludes tensioners). I'm tempted to go with them even though it does seem very expensive for an older car. The independent have a habit of finding something extra to charge me for bringing them close to the price of the main dealer anyway. Also it seems that the main dealer are better at fixing problems. They fixed my handbrake on their first attempt after the independent garage had failed twice to fix the same problem. I'm not sure I should trust the independent with the cambelt change either. Thoughts anyone?