What are the signs before a vehicle's timing belt breaks?

Timing belts are very important parts of motor vehicles. They are connected to the camshaft at the top and the crankshaft at the bottom. The piston and valve can work closely together in an orderly manner thanks to this belt.

It is a toothed belt, and no tooth can be wrong during operation.

It is made of rubber, just like other rubber parts on the vehicle, such as tires, oil seals, sealing rings, etc., which will age and wear out over time and with the increase of mileage.

Once it breaks, the rotation of the crankshaft and camshaft will be uncontrolled and there will be no connection.

There will be no signs before the timing belt breaks, which means that the degree of aging, let alone its remaining life, cannot be determined by eye observation. 

There is only one indication that serves as a warning sign, and that's the premature damage to the pulley. In the early stages of pulley damage, it often produces squeaking or scraping abnormal noises. Once these noises appear, we can definitely hear them. If you check and confirm that the noise is coming from the timing belt pulley, regardless of which pulley it is, it indicates that its service life has ended. It must be replaced immediately without delay. Otherwise, once the pulley seizes up, it will break the belt as well, increasing the damage.

Generally speaking, replacing a timing belt or pulley requires a lot of work, high technical requirements, and high labor costs. Therefore, they are replaced as a set. In addition to the belt, all the wheels also need to be replaced together to eliminate hidden dangers. 

So when should it be replaced normally? You can change it according to the mileage required in the maintenance manual, which is about 3-5 years, and the mileage is about 60,000-100,000 kilometers. Just like changing the engine oil regularly, you can change it at the time or mileage, regardless of whether it is abnormal or not, don't delay.

In addition to the timing belt, there is also an accessory belt on the vehicle, which connects the generator, air conditioning compressor, power pump, etc., and also has a fixed replacement cycle. The replacement cycle is generally similar to that of the timing belt, and it can be replaced when the timing belt is replaced. However, since this belt is exposed to the outside, the degree of aging can be observed with the naked eye, and it is not too late to replace it when it has many cracks. The process of replacing it is also relatively simple.

In short, when maintaining your vehicle, don't just change the oil, but also replace other parts that need to be replaced regularly. The timing belt is something that needs special attention. Once it breaks, the engine may need a major overhaul.