What Causes the Whine in The Alternator ?+ How you may Fix it

Most car owners hardly notice the sound of the car alternator as it is usually drowned out by the running of the car engine.

With all that being said, depending on the condition of the alternator or other components in the engine bay, you may pick up a whining sound.

Does this sound mean that the alternator is about to fail?

What is the cause of the whine and how can you fix it?

These are just a few of the questions you might have in mind when should you hear the whining sound from the engine bay.

So, in this post, I will share with you what can cause the whining sound in the alternator, what else might cause the whine in the engine bay, and how you may be able to fix it,

Common Causes of Whining Sound in Car Alternators

While there might be other causes of the whining sound in the engine bay, with the alternator, this sound may be caused by:

  • bad diode(s) can cause the whine in the alternator when it is a lot of demand for power from it
  • bad winding in the alternator can produce a noisy, whining sound
  • A failing alternator bearing though usually producing a grinding sound may produce a whining sound

Note, that this list is not exhaustive.

It is best to have the alternator tested at an Autozone to confirm whether it is faulty and if so, replace it with a new or refurbished one that fits your car model.

Can you Drive a Car with a Whining Alternator?

Yes, you might be able to drive with a whining alternator but you run a risk of getting stuck depending on the extent of the fault.

It is difficult to tell for how long you may be able to drive before the alternator fails, bearings seize, or the belt slips off the pulleys.

So, it is best you get the cause of the whining noise fixed as soon as possible.

Does the whining sound mean the alternator is about to fail?

Some car owners have shared that their car alternators have gone on to fail after producing the whining sound.

There is no reliable or consistent information about how long it takes the alternator to fail from the point it starts whining.

It may fail shortly after or you may be able to drive for a while longer.

be mindful that ignoring the whine from the alternator, risks sudden alternator failure and your car may fail to start without warning because the battery has not been charged sufficiently.

Are all Whining Sounds from the Alternator? Other Causes of the Whining Sound in the engine bay

While most whining sounds are associated with a failing alternator, it is possible for another failing component in the engine bay to be the source of the whine.

Examples of other components that may produce the whining sound are:

  • a faulty AC idler pulley
  • a faulty power steering pump

Note, that this is not confirmation of the fault. Have them checked out by a qualified car mechanic to confirm.

Therefore before you buy a replacement alternator, listen intently to where the whining sound is coming from.

Is it coming from the alternator or elsewhere? Some car owners have used a stethoscope to listen and confirm the source of the whine.

Note: You are dealing with a running car engine, take safety precautions when investigating the source of the whine or engage the services of a qualified car mechanic to assist you.

How to fix car alternator whine

If you suspect that it is a faulty alternator, you can confirm this by having it tested at the Autozone.

If it is faulty, replace it with one recommended by the manufacturer.

Related questions

How to fix car alternator whine in speakers

You can have the whining sound in your car’s sound system. This is more common with after-market sound systems such as amplifiers.

The sound may be noticeable when the car is idling, as you drive at a steady speed, and even increase as you accelerate.

Here are some suggestions that have worked for others and may help you too.

#1. Check if the cables to the speakers running next to the power cables. If so, try separating them as much as possible.

In some cases, car owners have recommended that they be run on opposite sides of the car – power cables on the driver’s side and the cables to the speakers on the co-driver’s side as an example.

#2. Check the grounding for your sound system. How good is the ground from your amplifier?

Make sure that the amplifier is properly grounded.

The ground connections should be firm and make contact with the exposed part of the metal or chassis.

There is a grounding point usually provided on the aftermarket sound system.

Also, keep the ground cables as short as possible to minimize the pickup of interference.

#3. Consider purchasing a noise filter for your sound system to filter out the noise from the sound system.

Consult the aftermarket sound system supplier on if you should install one and the recommended type to use.

Final Word

If your alternator is whining, it might be because of a bad diode, winding, or bad bearing.

Usually, if there is a whine, there is a good chance that the alternator will fail though it is not easy to say how long it will take to or what distance you can travel before it fails.

Once you trace the sound to the alternator, have it tested and replaced as soon as possible.

Keep in mind that there are other possible causes of whining, so it is important that you listen carefully to confirm the source of the whining before you spend any money.

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