Can You Spray WD40 on a Serpentine Belt?

Your serpentine belt is an important part of your car, and you don’t want it to break. You won’t be able to drive your car until it is replaced if it does. This long rubber belt is responsible for taking power to your engine accessories, including the air conditioning compressor, the power steering pump, and the alternator.

If you hear a squealing noise, it could indicate that your belt is slipping. People often want to spray it with WD40, and you can do this as a temporary fix. You can spray just enough to cover the area where the squeal is happening. Do not soak the belt, as this can cause it to slip.

The important thing is to make sure that you address the underlying problem that is causing the belt to squeal.

Using WD40 on squealing serpentine belt.

What Is the Serpentine Belt?

The serpentine belt connects all of the engine accessories, and it transfers power to them. Some people call it a fan belt or an accessory belt because cars in the past had different belts connecting the engine to the different accessories.

Today, most cars have one belt that is used to power all of the accessories by winding through a series of pulleys. It is more efficient and more reliable, but if the serpentine belt breaks, you will lose all of the components that it powers.

Why Is My Serpentine Belt Squealing?

The serpentine belt is designed to last a pretty long time, but over time it will break down from heat and friction. One of the signs that it is starting to slip is a squealing or chirping sound. You might hear it when you start your car, when you accelerate, or when you are turning.

When your serpentine belt is going bad, the squealing comes from the front of the car, and it is loud. It sounds like a squeak or a chirp. The squealing is fairly persistent, and it gets worse when you accelerate. This is why people want to spray it with WD-40: they want to make it stop.

There are different reasons that your serpentine belt might be squeaking, including the following:

Wear and Tear

Over time, your serpentine belt can stretch. When it does, it may slip on one or two of the pulleys, which will cause a squeaking noise. The belt could have some wear on the grooves of the ribbed side, or the edges may be worn.


The serpentine belt can slip from misalignment. This will cause different levels of pressure, and it can develop a glazed look and feel. It could end up causing problems with your battery charge, your radiator, your power steering, or your air conditioning.

Belt Improperly Installed

If the serpentine belt isn’t installed correctly, it can cause a squeak. It affects the tension of the belt and can lead to other damage as well. It needs to connect through all of the pulleys, or the tension will be off. This happens when people replace the serpentine belt on their own.

The Weather

If you only notice your belt squeaking when there is a heavy morning dew or fog, there is probably moisture on the belt. You will notice that it goes away once the engine warms up and the belt dries. You may also hear squeaking when it is cold out, as the cold weather will cause the rubber to be stiff. It will loosen when the engine warms the belt up.

Contamination From Oil or Grease

If you notice that the side without ribbing is shiny, there may be oil, coolant, or grease spilled on the belt. These products will cause the rubber to deteriorate, and it will lead to squeaking. You should look for the source of the spill and get it repaired.

What to Check If Your Serpentine Belt Is Squealing

When you have a squeaking serpentine belt, there are different possible causes. You need to know what it is so that you can repair it or replace it. You should examine the serpentine belt and look for signs of wear.

Look for cracks, worn edges, sections where the rubber has thinned out, and other defects. You should look for parts that are shiny or discolored, as well as any areas that are wet. If you notice any issues with the belt, you should replace it and diagnose the cause so that you can fix it.

Can You Spray the Serpentine Belt with WD-40?

If your serpentine belt is squealing, you can spray it with WD-40 as a temporary fix. When the belt starts slipping, which causes the squeal, it usually has excessive moisture on the ribbed side. WD-40 is an anti-moisture lubricant, and it will help to dry it out, which stops the squealing.

WD-40 Original Formula, Multi-Use Product with Smart Straw...
  • DRIVES OUT MOISTURE: Drives out moisture and...
  • CORROSION INHIBITOR: Acts as a corrosion...
  • Gets under grease, grime, gunk, gum, tar,...

You should always wear safety glasses when you spray the serpentine belt with WD-40. When you spray it, make sure that you use short blasts so that you lightly cover it without saturating it. If you spray too much WD-40 on it, it can permanently damage the belt.

If the belt starts squealing again shortly after you spray it, it is likely that you need to replace it quickly. This belt runs so many different engine accessories, so your car won’t work at all if it breaks. Use the WD-40 to get it someplace where they can replace the belt for you.

Will WD-40 Damage the Serpentine Belt?

WD-40 will damage the serpentine belt, which is why you should only use it as a temporary fix. It is a petroleum-based product, made of 50% Stoddard solvent, 25% light oil, and 12% to 18% LVP Aliphatic Hydrocarbon. They also have a secret ingredient that they don’t disclose.

Petroleum products cause rubber to swell and deteriorate, so it isn’t something you want to use unless you know you are going to replace the belt. When you are looking to lubricate rubber, you should use silicone or a dry Teflon lubricant.

Spraying the serpentine belt with WD-40 will make the squeal disappear for a while, but it will not fix the problem, and it adds damage to the belt. The only reason to use it is when you plan to replace the belt and want the squealing to stop.

Final Words

If your serpentine belt is squeaking, you can use WD-40 as a temporary fix, but you will need to address the source of the noise.




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