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Can You Spray Wd40 on Serpentine Belt or Pulley? (Answered)

Wd40 is basically used for the prevention of rust corrosion, resists metal from getting moisture, lubricates a very good number of things. 

But for serpentine belt or pulley, minor or major disturbances will be created if it is applied not following the perfect procedure. Again, some may get confused if it is right to apply wd40 on serpentine belt or pulley.

Here we are going to help you provide the required information so that we can drive away your problems. 

Can you use wd40 on serpentine belt or pulley?

You shouldn’t use wd40 for driving away the squeaky noise of the serpentine belt and pulley. Wd40 corrodes the rubber components. It also makes the squeaky noise worse. It can also damage the engine bearings and other components. So, for the betterment of the components, you shouldn’t use wd40.

The ‘wd’ in wd-40 stands for ‘water displacement. Although it’s called a lubricant, it is actually a type of oil which is designated in such a way that it can make its way into spaces between metal, eradicate moisture to resist rust. That is, wd40 is not an actual lubricant whatsoever. 

However, serpentine belts make squealing noise generally when they are on their way to becoming redundant. With days passing by, the rubber gets hard, and wd40 makes it worse by making it more slippery.  

Misalignment in the belt causes it to make noise. Tensioners may wear out or there may be stretching of the belts if you happen to use this so-called lubricant on a serpentine belt.  

As time goes by, some of the serpentine belts have a tendency to get cracked, which precedes making a squeaky noise. In this case, wd40 won’t help as it is not made to repair the cracking issue. Overall, it’s not a safe idea to use wd40 on a serpentine belt.

How to make a serpentine belt or pulley stop squeaking 

Serpent belt or pulley doesn’t make squeaking sounds when it’s well maintained. One should have expertise in following the proper methods of managing a serpentine belt to stop hearing unpleasant sounds from his car.

If making the serpentine belt or pulley stop squeaking is a thing revolving in your mind, then here are some tips for doing that –

Dielectric grease:

Dielectric grease is found in many forms in the market. It should be used every 6-8 months on a particular vehicle for reducing the squeaking.

First, wear gloves on hand and then put an inch of dielectric grease on your finger. Take a flashlight so that you can see where the ribs are.

Rub your finger (where the dielectric grease is put) right across where the ribs are. Then start your engine and let it run for 5-10 seconds. 

Permatex 22058 Dielectric Tune-Up Grease, 3 oz. Tube

303 aerospace:

It is a good medium for stopping the squeaky noise of the serpentine belt or pulley. Apply it on the serpentine belt and then use microfiber on all sides to wipe off the excess of the protectant.

303 30350 Aerospace Protectant 32oz

Bar of Soap:

Bar of soap is the only thing among household things that can stop squeaky sounds. Take a piece of soap, apply it on one side of the belt first.

Then make the belt rotate in all of the four directions. Rub the piece of soap gently on all sides. Wait for 5-10 seconds, then start the engine. You will see that the squealing is gone.

Carburetor cleaner:

If your car is squeaking annoyingly, then take the belt off, and some carburetor cleaner, stiff bristle brush, and some wool. Take a 3/8th ratchet that can be used to remove the belt. Then use the carburetor cleaner right on the belt. Carburetor cleaner should be used for 2 reasons –

i) It is very good at cleaning. It cleans grease and grime very quickly.

ii) It evaporates very quickly.

Gumout 800002231 Carb and Choke Cleaner, 14 oz.


The cost is very inexpensive if you want to replace your serpentine belt or pulley. The belt costs around $25 – $75. Sometimes it goes upto $100 but usually not more than that.

The labor cost for replacing the belt is $35- $120. Sometimes, it gets too difficult in the installment process. As a result, the mechanic may charge more money.

There are other methods of stopping squeaky noise such as – using crayons, talcum powder, etc. But the sound will come back within a very short time after you’ve put these things on your engine.

So, it will be better if you don’t resort to these items for fixing the issue of your belt or pulley.

Where do you use wd40 on the serpentine belt?

Wd40 should be used right onto the belt where the squeaking is coming from. For diagnosing the belt to know where the sound is coming from, the usage of a stethoscope is necessary and most effective.

Wd40 should be lubricated sideways of the pulley. Rubber components should be fully covered with this lubricant. Be careful so that wd40 doesn’t get dispersed around the belt.

Does wd40 damage the pulley?

After using wd40, there don’t occur any certain changes in the pulley, which means it doesn’t damage the pulley. But if the purpose of applying wd40 is to stop making unpleasant sounds, then it worsens the situation.

Squeaky noise needs solutions but using wd40 isn’t one of them because it is not made for this purpose. There are possibilities of the belts getting their components ruined up if you use wd40. So, it is highly recommended not to use wd40 on the pulley.

How do you lubricate an engine pulley or belt?

Lubricating an engine pulley or belt is not a hard task at all. Let’s show you how to make your engine pulley properly lubricated step by step.

Consider safety equipment:

Usually, the lubes that are used on pulleys are spray lubes, and not tube lubes. So, there is no need for wearing gloves.

Diagnose the sound source:

Use a stethoscope to figure out where the sound is coming from. You’ll hear different sounds in the places from where squeaky sounds are coming.

Apply lubricant:

Then apply lubricant right on the places. Putting your hand right on the belt may turn out risky, so you should refrain from doing so.

For the full-fledged application of the lubes, you can make a little bit of smudging of the lube by applying it all over the belt.

Check if the lubrication is done properly:

Start your engine after the lubricating is done. If it runs after a short time (especially 5-10 seconds), then lubricating was done in a proper way.

If not, then the whole operation needs to be done again or a different lubricant should be used.

Thus, engine lubrication is completed. One has to have proper insights about using a lubricant on engine pulley or serpentine belts. Instead of wd40, you can use a PTFE (Teflon spray) or white lithium grease.

Why does my serpentine belt squeal after replacement?

There are multiple causes of squealing even after replacement. If the tensioner is not good enough, the belt will be noisy. Thus, you may want to change the tensioner of your car.

If the grooves of the belt and pulley are not aligned properly, then the squealing noise persists. So, remove the belt again and make it seated on perfectly by following proper instructions.

How do you know what noise a pulley makes?

A pulley makes a squealing noise. Identifying the pulley which is making noise is significant for the management of squeaking issues. Using wd40 on the belt helps to find out which pulley is making noise as wd40 quiets up if it’s used on a noisy pulley.

You can also use a screwdriver in this case. Use the end of the screw on the pulley. But you have to ensure beforehand that the pulley is a non-moving area.

Make a fist with the help of a screwdriver hand and then keep your hand on your ear. Then it will be conspicuous which pulley is making noise.

How to clean belt dressing off pulleys?

Belt dressing is basically done so the belts don’t get dried out. It is also done as a preventive measure for the belts getting slippery, which leads to squealing. “ABRO belt dressing” is a good choice if you want a perfect noiseless serpentine belt.

Removing the belt dressing can be done by using dish soap and water mixture. Splash the mixture to the belt to rinse the dressing and clean it with water to make it free from any residue.

Final thought

Wd40 is a good thing for fixing metal-metal frictions, but serpentine belts have a way of getting corroded if wd40 is used on them. The squeaky noise doesn’t go away with the help of wd40. So, owners should resort to some other means apart from using wd40 for squeaky noise.