Belt & Tensioner

If you hear chirp or squeal sounds when driving your car, you can suspect that the engine belts are not working correctly. Faulty belts reduce engine transmission power, have steering and other problems. Most modern cars have just one or two belts. There are mainly 3 kinds of belts: fan belt, alternator belt and serpentine belt. The serpentine belt is a single continuous belt that drives accessories installed on the engine such as the alternator, power steering pump, water pump and air conditioner compressor. This belt is supported by an idler pulley or spring-loaded tensioner to keep drivers from slipping. The timing belt is located outside the engine but is routed over multiple gears for engines with multiple camshafts. This belt is easy to manufacture and assemble as it does not require oil for lubrication. The normal replacement period is between 60,000 to 100,000 miles.

The drive belt is made of sturdy rubber and degrades when it comes into contact with petroleum products or other chemicals. It gets damaged due to loss of engine cooling which quickly renders the vehicle unusable. Although the belt usually lasts up to 75,000 miles, replacement is recommended at the 45,000-mile mark. The toothed, reinforced belt used to drive the camshaft via a sprocket to a crankshaft is known as the timing belt. This belt ensures synchronization of the engine's camshaft, crankshaft and distributor. It also maintains accurate synchronization required to keep the engine’s valves and pistons moving in sync. Its hoses and steel lines transfer coolant, brake fluid and fuel throughout the vehicle. Over time, these parts may crack, rust or leak. In general belts make less noise. They stretch and loosen and cause whining noise before breakage. This is an indicator of a failing belt and that it requires replacement. It is easier to replace a belt because it takes less time and less labour charges. Many engines have a timing chain instead of a belt.

A timing chain requires replacement after 150,000 miles. It has less chance of breakage or damage but will tend to start stretching. A severely stretched chain could jump teeth, will have timing issues and might damage engine valves. Replacing a worn out timing chain is expensive and time-consuming. If either belt breaks, the vehicle will come to a halt. Once a timing belt breaks, the engine shuts off and you will not be able to restart it. Even if you are able to restart the engine after an accessory drive belt breaks you will not be able to get far if it does not drive the alternator. Without the alternator, you will end up relying on electrical power from the battery, which will not last, very long.