an apparatus for tensioning a chain is provided that compensates for the affect of temperature on oil viscosity by providing , in addition to a continuously open oil leakage path , an additional leakage path open only at lower temperatures when oil is more viscous and leaks at a slower rate . thus , overall oil leakage at lower temperatures is similar to that at higher temperatures , when the additional leakage path is closed , and the less viscous higher temperature oil leaks at a faster rate from the continuously open oil leakage path . accordingly , the affect of temperature on hydraulic stiffness of the tensioner assembly is minimized .