Symptoms of timing belt failure

Updated July 19, 2017

Proper timing is key to having a smooth running vehicle. The timing belt is a major component to a properly timed vehicle. It is vital to keep the timing belt in good operating condition. A broken timing belt can cause major problems with your engine. Fortunately, a timing belt usually gives some warning signs before it breaks.


The timing belt has the simple but important job of connecting the crankshaft to the camshaft. The crankshaft controls the engine's pistons and the camshaft opens and closes the valves, according to The valves would not be able to open and close without the timing belt, thus preventing the engine from running. A worn timing belt cannot perform its job well, which in turn causes performance problems.

Failure Symptoms

There are several symptoms of a worn or frayed timing belt. Be sure to see your mechanic if you experience rough idling, difficulty in starting or hear strange noises coming from the engine. As with many automotive problems, see your mechanic at the onset any of these symptoms. Delaying that inevitable trip to the mechanic will more than likely make the situation worse as the miles go by.


Engines are either of the interference or non-interference type. Little to no damage will occur when the timing belt breaks in a non-interference engine. But a broken timing belt in an interference engine can be catastrophic. That's because when the belt breaks the valves could then be struck by the pistons, resulting in major damage to the engine. Such damage could lead to a repair bill in the hundreds of dollars, according to Car Talk.


Changing a timing belt is not easy. According to, you must first drain the radiator and disconnect numerous parts, including the alternator, water pump, power-steering unit, air filter cover and distributor cap, fan belt and fan assembly, radiator hose and fuel line. It's also a good idea to replace any worn-out belts, hoses and clamps in the process. Therefore, you may want to take your vehicle to a mechanic to have the work done.


You don't have to wait until disaster strikes before changing a worn timing belt. Checking the belt during routine maintenance is a good way to avoid problems. Change the belt at the proper mileage intervals recommended by the manufacturer also. You can find the intervals in your vehicle's owner's manual. It's a lot cheaper to replace the belt before it breaks than to wait until it breaks and damages the engine.

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About the Author

Jeff Barron is is a 12-year newspaper veteran. He wrote for the Ocean County Observer in Toms River, N.J., the Ocean County Reporter, and the Portsmouth (Ohio) Daily Times. Barron won an Ohio Associated Press award for investigative reporting in 2004. He holds a Bachelor of Arts in English from Shawnee State University in Ohio.