Common Fixes to Reduce Alternator Pulley Noise and Restore Quiet Operation

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If you hear a squeaking, squealing, or an irritating noise coming from your vehicle, it most likely originates from your fan belt, alternator pulley, or from the modern serpentine belt. Fortunately, regardless of which one is the source of the noise, the steps for troubleshooting and fixing it are still the same.

The first step to troubleshooting a noisy alternator pulley is to locate and thoroughly inspect it. Turn off the vehicle and press down on top of the belt, taking note of how much slack is present. Most belts should not depress more than one half of an inch; more stress indicates the belt may need to be tightened or replaced. If the belt or pulley is broken and/or damaged, do not proceed to the next step and instead consult a mechanic to have it replaced completely. Additionally, if you find that the belt or pulley is excessively loose – that is, it can be turned more than a full 360 degrees – this will require professional attention as well.

Common Fixes to Reduce Alternator Pulley Noise and Restore Quiet Operation

Common Fixes to Reduce Alternator Pulley Noise and Restore Quiet Operation

Once you’ve located and inspected the noisy pulley, you can attempt to get rid of the noise by applying a belt dressing to the affected area. First, turn the vehicle on and apply the lubricant while the engine is running. Observe and listen to the engine’s sound; if the noise persists despite the lubricant, move on to the next step.

Common Fixes to Reduce Alternator Pulley Noise and Restore Quiet Operation

This next step involves applying a dish soap solution. To do this safely, turn off the vehicle and don’t touch anything while the engine is running to avoid accidents. Using your fingers, apply a nickel or quarter-sized quantity of dish soap onto the affected area. Make sure to spread the soap into the side and inner area of the noisy belt or alternator pulley, coating the affected area as far as you can reach. After application, check the noise level of the engine once more when you start the vehicle. The result should be much quieter compared to before.

Although these troubleshooting steps should help alleviate the problem, you should keep in mind that they are not permanent solutions and will not fix any non-functioning component of the engine. If the noise persists or returns and you see smoke coming out from the belt or pulley, take the vehicle to a trusted auto shop and let the mechanic take care of it.

  • July 2, 2020