You may not notice that your timing belt needs to change until it is too late. The timing belt may be cracked, the water pump broken, and/or the tensioner (hydraulic piston) malfunctioning. One or more of these issues cause a jump in timing and result in bent valves, a damaged engine head, and bent or broken pistons. Read your auto manufacturer?s manual to see at which intervals you need to replace the timing belt to prevent costly repairs.