About noisy alternators:

There are many different parts that spin inside the vehicle’s alternator to produce an electrical current. If one of these parts becomes worn or breaks, this could cause a grinding or whining noise. Specifically, worn-out bearings inside the alternator have been known to cause this type of noise. If the bushings that the alternator is mounted on have become faulty or worn, noise will also be produced. Alternators are normally replaced as a complete assembly.


What does a noisy alternator sound like?

A common noise from a failing alternator is a high-pitched whining or whirring sound. This noise is typically caused by worn-out bearings within the alternator. As the bearings wear down, they can produce a continuous or intermittent whining noise. However, you may hear clicking noises too. A clicking noise from the alternator can indicate a problem with the electrical connections. Loose or corroded wiring, faulty diodes, or a defective voltage regulator can cause intermittent clicking sounds.

Reasons for noisy alternator:

1. Alternator belt problems

An excessively worn, cracked, or loose alternator belt can produce unusual sounds such as squeaking and squealing, as can an alternator belt that is out of alignment.

Solution: Check the alternator belt for wear or looseness. The excessive material loss may be preventing the belt from fitting the alternator pulleys properly, or the belt may be cracking on either the ribbed side or on the flat backside.

Replace or tighten as necessary, making sure the belt is properly aligned on the pulley. Do check the pulley flanges, as bent pulley flanges are a common cause of belts running out of alignment. Improperly aligned alternator belts will often produce a whining sound. Fixing a misaligned belt may also eliminate the noise.

2. Loose alternator bolt

Sometimes, an improperly mounted alternator can produce noises (and battery connection problems) that can lead to failure.

Solution: Often, a loose or missing alternator pivot bolt or adjustment bolt can be the source of the problem. It’s critical to make sure your bolts have a snug, secure fit to keep your charging system operating properly.

3. Failing alternator bearings

The alternator contains internal bearings that allow the rotor and other components to rotate smoothly. Over time, these bearings can wear out due to age, excessive heat, or inadequate lubrication. Worn-out bearings can produce a whining, whirring, or grinding noise.

Failing alternator bearings can produce a persistent whining or grinding noise up to the point

of total failure. There are bearings that allow the rotor to spin freely inside the stator housing. They can break down from excessive dirt and heat. When the bearings fail, the rotor won’t spin efficiently and can eventually, seize. A seized alternator bearing tends to destroy your alternator belt with it. In either case, an alternator that isn’t charging your battery can find you roadside with a non-functioning car sooner or later.

Solution: Replace your failing alternator bearings, or replace the alternator itself.

4. Misalignment of the alternator pulley

The alternator pulley should be properly aligned with the other pulleys in the accessory drive system. If the pulley becomes misaligned or loose, it can cause the drive belt to slip or create friction, resulting in a squealing or rattling noise.

Solution: Realignment of the pulley and repositioning of the drive belt as needed.


Noisy alternator inspection and replacement in Hamilton

Does your car have a noisy alternator or drive belt? If so, we can help!

At Grimmer Motors, our team of skilled, honest mechanics can replace your car’s alternator or drive belt for you. This will get rid of annoying/embarrassing noises, and keep your car battery charging correctly to allow your car to start every time without an issue.

Usually, it is more cost-efficient for you if we replace the entire alternator. As well as fixing the excessive alternator noise, a new alternator will be more reliable in the long term and less likely to fail.


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