The toothed belt is an internal motor component that rotates the engine's cam and crankshaft in synchronization and ensures each cylinder fire at the right time. The toothed belt is located under a timing cover and is at the front of the engine. It is usually manufactured from high quality rubber with nylon reinforced wires inside to extend the life of the belt. But it is subject to incredible power inside your engine and needs to be replaced eventually. Without a fully functional belt rod, your engine will not run.
Not all engines have a lane. The toothed belt is commonly found in cars and SUVs with smaller displacement motors. When a motor has a larger bore and stroke, most car manufacturers use a timing chain system that replaces the rubber band with a metal chain. Generally, timing chains remain longer than timing belts, with some estimated to last the life of the car. Most automakers have a predetermined recommendation on when
to replace the belt, but there are a few warning indicators that have a problem.

Below are a few common symptoms that may indicate that your belt is worn or broken - which will require a certified mechanic to replace the belt and inspect other internal engine components for damage.

1. Ticking noise from the engine:

The toothed belt is attached by a series of pulleys to the engine crankshaft and camshaft. The crankshaft controls the engine's connecting rods which are attached to pistons within the combustion chamber. The camera shaft drives cylinder head valves and rocker arm assemblies which send fuel into the combustion chamber and emit burned gases out of the exhaust manifold. When the belt starts to wear out, it can create a ticking sound inside the engine. This warning sign may also be a sign of low oil pressure, or if the engine does not have the proper lubrication rate.
As the belt is so critical for the operation of your vehicle, contact a mechanic as soon as possible if you notice this warning sign.

2. The engine does not turn over:

If the belt is broken, the engine cannot turn or ignite. When you turn the key, you can hear that the starter motor is engaged, but as the drive belt activates crankshaft and camshaft, it will not turn around. Of course, if the car does not start, a phone call to a mechanic is usually the first step. However, if the problem is that the belt is broken, it may also cause damage to the inner engine compartment. In many cases, the hour band will break while the engine is running. Some of the typical damage done to a vehicle with a broken hour band involves damage to the cylinder head hardware (rocker arms, pressure rods or valves), damage to the crankshaft or the oil pump inside the oil can.
A professional and experienced mechanic will know how to inspect all these supporting components if the belt is to be replaced.

3. Misfiring of Engine

A worn timing belt can also affect engine firing rate. The timing belt is attached to the pulleys that drive the crankshaft camshaft, as we indicated above. However, sometimes the belt will slide along the camshaft drive and force one cylinder to open or close earlier than it should. This can cause a misfire and, if not replaced in the near future, can lead to catastrophic engine damage.

4. Oil leak from the front of the engine

It is also typical that the engine will leak engine oil from the timing belt cover. The cover is attached with a series of nuts and bolts that can loosen over a period of time. Another problem that can cause an oil leak is when the gasket between the cylinder block and the timing cover wears, cracks or is improperly installed and clamped. Leakage of oil from the timing belt cover also leads to engine overheating and may wear the timing belt prematurely. However, consult a professional mechanic.

Source:
http://www.eliancars.com/2019/01/symptoms-of-poor-of-failing-timing-belt.html
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