Why Do My Serpentine Belt Squeal on Startup? How To Stop?

Engine belts, such as the timing belt and serpentine belt, help the engine time and run its various components. If the engine makes a screeching or squealing noise when starting, particularly in cold weather, the engine belt probably needs to be replaced.

In this article, we’ll walk you through this matter and help you understand a bit more about this issue coming from your serpentine belt. This way, you’ll have a sense of what to do if it ever happens in your car. Let’s get going at once!

Why Does My Serpentine Belt Squeal?

Even a brand-new serpentine belt can squeal if the tensioner pulley is worn out. In other words, even though the belt is new, you can’t guarantee that your car will stop screeching.

When the car is accelerating or starting up, the serpentine belt frequently makes a screeching sound. To put it another way, your engine is heavily taxing your alternator at these times.

Under such a great load, a worn-out belt and tensioner pulley might shriek. You may still hear that squealing noise even if you have replaced your belt and installed a new one. This is due to the pulley’s potential continued wear.

As the rpm rises, this noise will become more audible because it is caused by a relative sliding between the belts and pulleys, as has already been mentioned.

How to Stop My New Serpentine Belt from Squeaking?

Generally speaking, before you do anything, you should determine the source of the squeaking sound. It will typically be on the belt and pulley. If the belt is not kept continuously attached to the various pulleys, it begins to slide and scream. Belt squeals are frequently caused by humidity on the side of the belt with ribs.

If your belt is a new replacement, you should first inspect the pulley. Here are some things you can do to stop your new serpentine belt from squeaking:

Do Some Thorough Checking.

Start your car by lifting the hood of the engine compartment. Maintain a safe distance between your arms, clothing, and the motor and its components.

Look for a spot where you can spray WD-40 on the belt so that it covers the textured side right away before it passes through a pulley. Use light to help you find this spot.

Find the sound and search for a link between the sound and belt movement. In this manner, you can pinpoint the precise location from which the squealing is coming.

Why Do My Serpentine Belt Squeal on Startup? How To Stop?

Lubricate the Belt.

Wear your protective goggles and avoid standing directly in front of the belt, as the spray will tend to fly out in a path, staining your clothes.

Spray an adequate amount of WD-40 to gently coat the region where the scream occurs on the belt. Use brief, swift blasts to prevent the belt from becoming saturated.

Remember not to lubricate the belt too thoroughly as you do this. Spraying too much will result in serious slippage and destroy the belt. Additionally, because WD-40 is a water-displacing lube, it ought to dry out the belt ribs.

Once the moisture is gone, the scream usually comes to an end. Before applying rubber treatment, also referred to as belt dressing, to the belt as previously described, let the motor run for a short while.

The belt’s ribbed surface will be thoroughly cleaned using this technique, removing any impurities that may still be present. When using WD-40, do not oversaturate the belt. To ensure that the noise has completely disappeared, run the engine for a few more seconds.

What to Do If the Squealing Noise Continues:

The serpentine belt is glazed if the scream does not cease or returns rapidly. Belt glazing occurs after it has slid across the surface of one or more pulleys for a considerable amount of time, and it is typically noticeable as a reflecting shine on the textured sides.

A glazed belt will scream and needs to be replaced because it can no longer keep a hold of the pulleys. Please make a note of the belt’s route before pulling it once you’ve determined that it needs to be replaced.

A route map is typically located underneath the hood of most cars or close to the engine. Before removing the belt, make sure that all of the pulleys are spinning. A stuck pulley is frequently the cause of a glazed belt, and it is usually a sign of a bigger problem.

What to Do When the New Serpentine Belt Squeals When Accelerating?

Because the engine puts a heavy load on the alternator, which is connected to the belt, the new serpentine belt squeals when moving forward, just like an engine starting.

The air conditioner, cooling system, alternator, and power steering pump are all driven by a serpentine belt. Acceleration places a heavy load on the alternator, which can make the belt squeal from the extra work.

Due to the belt’s size, a belt tensioner aids in keeping it taut and is simple to take out and replace. When the car accelerates, the belt, if it’s worn, could slip and scream. The belt might also scream if one or more of the alternator’s pulleys is worn out or loose.

The most typical sources of squealing are serpentine belts that are worn out. Therefore, if you have a new one, the pulley is probably the source of the issue.

What you can do is lube your belt a little with WD-40, which will also help displace any water or moisture in it.

Final Thought

The serpentine belt squeals even if it’s a new replacement, even if it’s brand new. The serpentine belt makes a lot of effort, especially when the car is starting or accelerating, which causes it to squeak.

Find the source of the screeching sound and see if your pulley needs to be replaced. You can also use WD-40 or another water-displacing lubricant to quiet the motor if necessary. One thing to keep in mind is that over-lubricating the belt can lead to its breakdown.