How to Troubleshoot a Noisy Alternator Pulley

What You'll Need
Silicone spray or belt dressing
Dish soap or bar soap

If you hear a squeaking, squealing, or an irritating noise coming from your vehicle as it runs, it could be from your alternator pulley. Not only is this noise annoying, but a slipping or loose pulley could mean other problems in the future if not fixed. This article will teach you how to troubleshoot your alternator pulley to eliminate the noise. It’s a simple method that you can actually do by yourself even in the comfort of your home, without incurring much cost. So, instead of going to the nearest vehicle repair shop, give these instructions a try!

Step 1 - Identify the Source

This kind of noise may originate from your fan belt, alternator pulley, or from the modern serpentine belt, so you will have to figure out which one is the perpetrator. A good way to tell if it's the alternator pulley specifically is to listen for whether or not your automobile wails even before you touch the steering wheel. You may also check which belt is the problem by applying a few drops of brake fluid on the running engine. If the belt or pulley immediately goes silent, then you know what needs attention. Fortunately, whichever of these belts is the cause, the rest of the steps for fixing them are still the same.

Step 2 - Do the Initial Inspection

Locate and thoroughly inspect the noisy belt. Turn off your vehicle and press down on top of it. Make sure to leave some limp and let the belt decrease an inch. Otherwise, when there is more air on it, the belt may need to be tightened or replaced to effectively get rid of the noise.

Do take note if you see that the belt or pulley is broken and damaged during your inspection. In this case, do not proceed to the next step but instead go directly to the mechanic to have it replaced completely. Also, if you notice that the belt or pulley is exceedingly loose, where you can turn it more than half of a 360-degree turn, then you should let a professional fix this for you as well. Your solutions might not be effective if the belt is too loose.

Step 3 - Apply the Spray

Turn the vehicle on and apply the silicone spray or belt dressing onto the affected area while the engine is running. Observe and listen to the engine's sound, and if the noise persists despite the lubricant, continue to the next step.

Step 4 - Apply the Soap

When applying the soap, make sure to turn off the vehicle; do not touch anything if the engine is still running to avoid accidents. Then, apply a nickel or quarter-sized quantity of dish soap on your fingers and spread in into the side and inner area of the noisy belt or alternator pulley. Coat the affected area as far as your fingers can reach. Then, do check for the noise again once your start the vehicle. The result should be quiet compared to earlier.

These troubleshooting tips are not permanent solutions and will not fix any non-functioning components of the engine. If the noise persists or returns and you can see smoke coming out from the belt or pulley, then take your vehicle directly to the nearest automobile shop and let the mechanic take care of it.