Once the tensioner is set to the correct spot in the window you’re done. That is saying, the specified tightness (tension) of the belt, itselfhas been achieved.
You are experiencing the tensioner doing its job. Keeping the belt under constant, equal, tension throughout the rotation of the entire belt and keeping the teeth of the belt in contact with the teeth on the pulleys.
What you’re seeing in the tensioner window is the stretch of the belt in different locations on the belt. Say minor imperfections. As you rotate the engine, that needle is going to move as the the belt passed around the tensioner. The same effect happens with accessory belt, minus the teeth. Mark that accessory tensioner and rotate the engine and your tensioner is going to move a bit, as it should.
Piece of mind? The tensioner pulley may be defective, like off center. Possible but not likely.
Proof in the pudding?
Put the old timing belt on, with the new tensioner. And rotate the engine by hand… the pointer should move a lot more compensating for the worn timing belt.
You are experiencing the tensioner doing its job. Keeping the belt under constant, equal, tension throughout the rotation of the entire belt and keeping the teeth of the belt in contact with the teeth on the pulleys.
What you’re seeing in the tensioner window is the stretch of the belt in different locations on the belt. Say minor imperfections. As you rotate the engine, that needle is going to move as the the belt passed around the tensioner. The same effect happens with accessory belt, minus the teeth. Mark that accessory tensioner and rotate the engine and your tensioner is going to move a bit, as it should.
Piece of mind? The tensioner pulley may be defective, like off center. Possible but not likely.
Proof in the pudding?
Put the old timing belt on, with the new tensioner. And rotate the engine by hand… the pointer should move a lot more compensating for the worn timing belt.