Rattle from Engine at All Speeds on Toyota Corolla

The timing chain tensioner is designed to use oil pressure to keep tension on the timing chain. When it develops a leak, it can no longer provide tension, and the timing chain will begin to make a slapping or rattling sound at all times.

If left in this condition, the timing chain may fail, leading to costly internal engine repair.

To correct this issue the timing chain tensioner must be replaced with the revised part.