What's wrong with the auto A/C compressor belt rattling?

In most cases, the belt squeal is a loose belt. When this happens, it is best to go to a repair shop to adjust the belt tension as the belt slips and makes a squealing sound. Once the belt slips, due to the high friction temperature, the belt will be further lengthened and the slipping will be more serious, leading to a vicious circle. Therefore, timely adjustment of belt tension is key. If you've driven almost 20,000 kilometers and haven't changed the belt before, it's basically time to change the belt now. Don't wait for the belt to break before you change it, you'll be in big trouble.

What can I do if my car belt is rattling?

A way to tell if the engine belt is rattling

First step:If there is an abnormal noise in the engine compartment of the car, it means that the belt is usually loose or of poor quality, so the first thing to do is to check the engine belt. If there are many belts in the car, we can't tell which belt is out of order. We can start the car and then pour some water on the belt. If the noise disappears, it means that there is something wrong with this belt, and we can see if it is loose or of bad quality.

The abnormal noise of the engine belt, pouring water is to increase its viscosity, which actually improves the viscosity of the belt. But after the water dries, the belt will return to its original shape, this is the principle of belt watering.

Step 2:We can also determine which belt has a problem by listening to the sound. If/when there is a problem with the steering wheel, there may be a problem with the steering pump belt. If there is an abnormal noise when the car starts cold, it may be a problem with the engine belt, which we can check step by step.

A way to determine and solve the abnormal noise fault of the engine belt

1. The engine belt squeaks.

This is because the belt and pulley bonding surface is relatively smooth. It usually occurs when the engine speed changes faster, and sometimes the load on the belt-driven accessories increases, which can also cause the belt to idle.

A squeaky belt usually means that the coefficient of friction on the belt surface has been greatly reduced and is excessively worn. If the vehicle is loaded with noise, it may be worthwhile to look at one of the drive belts and notice that there is an unusual increase in resistance or elasticity on the automatic belt tensioner or belt tensioner pulley.

Most automatic belt tensioners have a set of belt wear length indicators on the chute between the bottom of the belt tensioner and the tensioner arm. This consists of a pointer and two or three marks indicating the operating range of the belt tensioner. If the pointer is outside this range, the belt may be stretched too far and should be replaced. On cars without an automatic belt tensioner, use a standard belt elongation measuring tape between the two pulleys. If it differs from the standard value, it is best to replace the belt.

2. Engine Belt Makes Long Squealing or Harsh Noise

While a belt can make a long squealing or harsh noise when there is dirt on the surface of the pulleys, such as sand, or when a used belt is installed the other way around, this is usually due to improperly assembled auxiliary devices.

If the noise occurs on a new car that hasn't been driven for a long time, it could be due to poor quality original equipment. Check the visual components that you think may be causing the failure. If the above noise occurs on an older car, then you should consider whether you should completely replace some of the accessories associated with its auxiliary drive. Take a close look at the accessories that may have been finely replaced (e.g., generator, steering-assist pump, etc.) , and see if their mounting brackets are secure, which could also lead to misalignment of the pulley assembly.

Dust or sand between the pulley and the pulley can also cause a harsh noise, so if the car is used in a dirty environment, check the surfaces of all the pulleys for dust.

The timing cog belt, for example, should be adjusted immediately after installation. This is why the direction of rotation of the timing cog belt should be marked. If the timing cog belt is installed upside down during other maintenance, you'll hear a sharp, piercing squeal when the belt is running.

Try reversing the direction of belt installation and see if the fault goes away.

3. The engine belt makes a hissing, rattling, roaring or chirping sound.

A persistent hissing or clicking sound that increases with engine speed usually means the bearings in the auxiliary rotating mechanism are low on oil.

With the aid of a stethoscope, we can hear these noises further. Then, remove the drive belt and rotate the suspected faulty part by hand. If it is difficult to rotate or the sound is rough and harsh, or if it clicks and clatters, do not hesitate to replace the bearing or the corresponding part. It is important to note, however, that each time you replace parts for the sub-transmission attachment, don't forget to replace the belt elastic pulley and the automatic elastic mechanism.

As the engine speed increases, the constant roar gradually turns into a whining sound, indicating that the corresponding bearing will soon fail.

4. Engine belt rumble

Rumble is a typical sound caused by belt vibration, especially when the auxiliary mechanism of the drive system is running, when the engine reaches a certain speed, the noise will increase significantly. The cause of this failure is usually a drive belt that is too loose, stretched too long, or a damaged belt tensioner and elastic pulley.

If your car's engine belt becomes abnormal during the warranty period, it is recommended that you talk to your 4S store as soon as possible to negotiate repairs. Once it exceeds the warranty period, you may need to repair it at your own expense. Engine belts are automotive wear and tear products and need to be replaced regularly. Some models are very complicated to replace the engine belt. It is best for car owners to go to a repair store or 4S store for replacement.