A car engine can start to stall or fail completely if the timing belt is worn out or broken.
The initial cost of a timing belt installed in a car starts from around $500, but it can reach up to $1,500 or more depending on the work involved and state of other components. Under normal circumstances, replacing a timing belt should not take more than two hours but it depends on the vehicle age, make, model and availability of spare parts.
A timing belt is a strong rubber strap with teeth on the inner side. It is considered similar to a timing chain but there are a few differences between them.
A timing belt is relatively durable, lighter, less expensive, and quieter than a timing chains.
The belt is installed under the timing cover, which is in front of the engine. It connects to the engine’s cam and crankshaft. The teeth of the belt are responsible for the movement of these components.
In some cars a timing belt can drive other components of the engine such as a water pump, balance shaft, air conditioning system and many more components.The timing belt is responsible for the synchronisation of the the crankshaft and camshaft’s rotation. This allows the engine’s valves to open and shut properly at the correct time to facilitate a proper mixture of air and fuel to enter the cylinders.
Common signs of a bad timing belt include:
A bad timing belt will produce a ticking sound that can be heard when the engine is running. The ticking sound might indicate low oil pressure but in case the oil pressure is normal, the bad timing belt is probably the culprit.
The car’s “check engine” light can start flashing and in most cases, this is caused by a failing timing belt. Alternatively, it can point out problems with the camshaft or crankshaft correlation code.
The timing belt co-ordinates the camshaft and crankshaft to allow air and fuel to enter the cylinders. If the timing belt is broken, it will cause desynchronised cylinders. As a result the car might start hard, or misfire.
The car will start to move roughly due to improper engine operation and the engine can start to stall or fail often if the teeth of the timing belt are worn out and or broken. This can cause the gears of the crankshaft and camshaft to slip on the timing belt, causing the engine to fail or malfunction.
Timing belts are expected to last for 7 to 10 years or up to 100,000km,depending on manufacturer recommendations. According to some manufacturers, driving more than 80,000km on a genuine timing belt must be avoided and checking every few years or 60,000kms is a good rule of thumb. However, the recommended interval for replacing the timing belt is somewhat different. Car owners must ensure inspection and or replacement (if necessary) of the timing belt once every 5 years or after every 50,000 miles. If the timing belt is attached to many other components such as the water pump it can break down sooner than expected.
A professional mechanic in a workshop has a proper timing belt replacement kit that contains all the important tools required to replace the timing belt. Any installed accessories are removed so that the timer belt cover becomes accessible. The cover or shroud is removed to make the timing belt accessible - the belt is removed along with the tensioner and the idler pulleys. The mechanic will inspect and replace the water pump (if needed). The timing belt is then replaced. If required, the idler pulleys and tensioner are serviced and or replaced as well. If required, the cooling system is serviced as it can cause the timing belt to worn out sooner.
Ideally, the water pump is changed along with the timing belt because it usually fails after 200,000km. Many workshop mechanics recommend changing the water pump during timing belt replacement. The mechanic will replace or service the idler pulleys and tensioners. These parts have grooves that get worn out over repeated use, which can damage the new belt much sooner. It is advisable to replace these parts as well. If required, the mechanic may oil or grease the parts wherever necessary as a part of servicing. Some workshops do not provide a warranty on the timing belt unless you get all these parts replaced. These parts will be costlier if bought separately. They can be bought cheaper by buying a timing belt kit from a workshop.