signs of leakage. The tensioner assembly is simply a piston assembly mounted to a bracket which holds a bearing (idler pulley). To check it properly you will need to expose the front of the engine as though your going to replace the belt. Turn the engine over by hand until all the timing marks line up based on the crankshaft mark. If you have to release the tension on the belt to realign anything the FSM gives a step by step in the EM section. You will need to insert a 10mm bolt in the tensioner arm to and slowly adjust the arm to achieve the 4mm gap. Then loosen the bolts to the tensioner and remove the belt.