A timing belt is a mechanical tool that transfers motion to the camshaft from the crankshaft of a reciprocating internal-combustion engine and sometimes it also transfers motion to some of the engine driven accessories. By connecting crankshaft to the camshaft, it will keep the cams turning at the same rate as the crank at a certain variable ratio. It will make sure the right valves are opened at the right time every time a stroke is made by a piston.
So for simplicity let’s just say that piston connects to crankshaft, and crankshaft connects to camshaft, and camshaft connects to valve.
Timing belt is cheaper to manufacture than timing chains or gears, it’s also quieter when operated. A timing belt doesn’t need lubrication. But one disadvantage of timing belt is you need to replace it every certain interval.
When the timing belt slips just by one tooth, the engine stops operating. In several cars it will produce costly damage especially to the pistons and valves. When the timing belt drops or fails, you will not be able to start the engine. If this happens you should not try starting the engine again.
How to Check Belts:
1. Turn off your engine.
2. Open the hood of your car.
3. Find the belts, they are located on the very front of your engine. If you have a rear wheel drive car, the front of your engine is usually adjacent to the front bumper and the radiator. Otherwise if it’s a front wheel drive car then the front of of the engine is often adjacent to the fender.
4. Note that there are 2 or more belts, it depends on the car models.
5. Press lightly with thumb at the belt’s longest part between pulleys. Do this on each belt.
6. Find out the normal tension for your belts. It’s in the car’s manual. Normally belts cannot have more than one inch of “give” in both direction.
7. Evaluate those belts as you press them. If the belt is cracked or can be easily pushed more than one inch, then it’s highly advised to replace with a new one.
To prevent damage and costly repair, a timing belt should be replaced every 60,000 miles.