省時省力?... 主流換法是正時皮帶，水泵，張緊輪係統（怠輪 if any）通通換，否則 no point 換正時皮帶...

When the timing belt is replaced, other parts, including the tensioner, should be replaced at the same time. This is because these components wear out at essentially the same rate as the belt. For instance, the tensioner bearings could dry out or even seize.