Alternator bearing noise can be…unbearable. You would certainly want to get rid of it as soon as possible and, thankfully, it is relatively easy to do that.

To fix alternator bearing noise, turn the engine off, raise the hood, and remove the alternator belt. Inspect the bearing – if it is showing signs of wear and is producing a sound when you rotate the alternator, then the bearing needs to be replaced.

For how long can you continue driving with a noisy alternator bearing and what causes this component to wear out in the first place? You will find all the answers below.

How to Fix Alternator Bearing Noise

If you hear a high-pitched, whining sound or squealing, rattling, and grinding, instead of the regular humming coming from your alternator, then it looks like it’s the bearing producing the noise (you will usually hear the sound once you start the engine).

To fix the sound, you should:

1. Make sure that the car’s engine is turned off.
2. Raise the hood, locate the alternator belt and remove it – in such a way, you will have better access to the actual bearing.
3. Inspect the alternator bearing – use one hand to rotate the alternator and reach for the bearing with the other. If it’s the rotation that’s producing the sound and, on top of that, the bearing is not smooth, then the component is worn-out.
4. A worn-out bearing would have to be replaced. To do that, you should either replace the entire alternator or only the bearings. The latter option might be a cheaper and less time-consuming choice.

How to Check Your Alternator

The first thing that you need to do is find out if the noise is coming from the alternator or another car part.

1. If you hear a squeaking noise when you start the engine, then the chances are high that the worn-out bearing would be to blame.
2. To double-check that, jump-start the vehicle and take the power cables off – if the engine turns off, then your alternator is the issue, but if the engine continues to run, then it looks like there is something wrong with the car battery.

Another test involves the headlight:

1. Start the engine and ask someone to check the headlights.
2. Push the gas pedal – if the headlights are fainting or turning off completely, then the problem is with the alternator.

There are also a few tell-tale signs of worn-out bearings, including slow cranking, an empty battery, a seized rotor, and dim lights.

Why Is My Alternator Noisy?

Alternator bearings are practically always the root cause of a high-pitched, whining sound. 

With that being said, there are also other possible alternator malfunctions that can be causing noises:

• Loose bolts can lead to the failure of the alternator altogether. If the component is not tightly bolted to the engine, then it will not only produce strange noises but will also become a potential safety hazard.
• A worn-off belt will produce sounds as well. The belt is responsible for rotating the rotor and just like any other component that involves movement, the belt can get worn. By the way, the bearing and the belt work together, so if one of the parts is malfunctioning, then the entire set-up won’t be able to operate correctly.

What Causes Alternator Bearing Noise?

The bearings will start producing a sound once they go bad. This, in its turn, can be caused by the following reasons:

• Normal wear and tear – the alternator has a few moving components that will eventually wear down. If your car has covered tens of thousands of miles, then it might be time to replace the bearings.
• The belt is too tight – if the alternator’s belt is way too tight, then the bearings may start to malfunction over time. You have to make sure that the belt is fitted right and that it is providing the proper tension.
• Lack of lubricant – to prevent the moving components from wearing out, you have to ensure that they are lubricated.
• The alternator has been exposed to dirt, heat, and water – if you’re a fan of driving through high water, then the life expectancy of the alternator components and the car’s whole electrical system will get decreased. This will eventually lead to the premature failure of the bearings.

Can You Drive with a Noisy Alternator?

If there is something wrong with the alternator bearing, you will hear a dreadful sound once you start the engine. But the noise can sometimes stop as the engine’s speed increases – and that is exactly why a lot of owners decide to put off tackling the issue.

If you’re experiencing a mild noise issue, then the problem is in an early stage (it will get worse with time though). A constant noise means that the issue is already extremely serious and you should not attempt driving your car at this stage.

If you continue to drive the car, then the components might overheat and start producing smoke and an unpleasant smell. This can lead to:

• A failed alternator (which means that your car might be left without a power source at any time).
• A severely damaged alternator – in such a case, you would have to replace the entire component to fix the car. In the early stages, you might simply have to get a new bearing that is going to cost you around $30 or less. The costs of a new alternator can range from $300 to $1,000 for the parts and labor.

Conclusion

How to fix alternator bearing noise?

In the absolute majority of cases, all you would have to do is replace the worn-out components (it can be the actual bearing or the alternator belt). At times, you might have to get a new alternator.

You should avoid driving with a noisy alternator bearing as the components of your vehicle can easily overheat and get permanently damaged. Not to mention that driving such a vehicle is not safe.