The Purpose of the Timing Belt
The timing belt runs from the camshaft, which controls the intake and exhaust valves on your engine, to the crankshaft, which connects to the cylinders and provides up-and-down movement for them. For your engine to work correctly, the cylinder must be in the right place when the intake valve is opened, the combustion must be able to push the crankshaft correctly, and the exhaust valves have to open to let out the by-products of combustion. This is all controlled by the timing belt.
Old Timing Belts
When the timing belt gets old, it can slip, causing one or more components to become slightly out of sync. This lowers the performance of your engine and can lead to damage if more slips continue. If the belt breaks entirely, the entire system can get thrown out of sync, leading to large amounts of engine damage. Old belts can be replaced every 60,000-100,000 miles, so it’s best to keep an eye on the belt so that you know when to replace it.
Timing Belts vs. Serpentine Belts
Timing belts operate solely on the engine, keeping parts in sync so that combustion can proceed properly. The serpentine belt winds away from the engine, using the engine’s torque to run other systems, like air conditioning, power steering, the alternator, and sometimes even the coolant pump. Timing belts and serpentine belts are entirely different belts, but the timing belt can cause more damage to your engine if it gives out, whereas the serpentine belt may damage auxiliary systems.