Why Does My Car Squeak When It Rains?

Many of us love to ride in the rain, don’t we? That sweet melody of raindrops may make our minds lost in thoughts. Yet a disturbing high-pitched squeal from the car can change the mood melancholic. Yes, today I am writing the explanation of “Why does my car squeak when it rains?”

The squeaks start from the rain penetrating the inside of the vehicle. Then, it makes things wet, like the serpentine belt and creates noise. Besides, worn-out, aged stuff like rubber bushings, struts, and ball joints can be the reason a car squeaks in the rain.

That’s not enough! There are many more things to know if you want to sort out the squeaking issue in your car. And I am here to discuss them to ditch your earplugs and enjoy the rain without any disturbing sounds. Won’t you spend a few minutes learning them?

How Does Rain Impact Your Car Internally & Externally?

Rain can impact the way you drive and maintain your car. For instance, rainwater (or heavy rain) can cause damage to the exterior paint, windshield, and other parts (1). Once the rain goes away, it can leave marks stains, or even strip away the protective wax coating from a car’s paint.

Now, what about internal impact? More precisely, the squeaking noise?

Well, besides exterior damage, rain can also affect the internal components of your car. Rainwater can accidentally enter sensitive electrical parts like the engine bay or fuse box. It will lead to malfunctions or short circuits. In the same way, water can make things wet inside. Then, the consistent friction between those wet parts can cause unexpected noises.

Causes of Car Squeaking When It Rains

Let’s save time! In this part, you will learn the possible reasons for high-pitched squeaking from vehicles in the rainy season.

Wet, Slippery Serpentine Belt

The serpentine belt drives engine accessories like the alternator, power steering pump, and AC compressor. But it can cause a squeaking or squealing noise from the engine. Usually, it happens due to weather conditions like heavy rain or exposure to antifreeze (2,3,4,5).

When the belt gets wet, it reduces its grip on the pulleys it spins. This slippage creates friction, the belt starts to slip, and produces a squealing noise.

Worn or Cracked Serpentine Belt

Let’s think that water cannot penetrate the internal parts of the vehicle engine. Another common reason for squealing would be a worn or failing serpentine belt. It can cause engine overheating for the water pump not functioning correctly (6, 7). Yes, the engine may get overheated, yet it rains.

Some signs of a bad serpentine belt can be a poorly charged alternator or weak power steering (8). Other symptoms include loss of power steering, lack of air conditioning, and warning lights on the dashboard (9). When the belt breaks, your car will lose power to all engine-driven accessories.

Wet Brake Pads

Rain can bring about several changes in your car to make it produce unusual noises. So, have you checked the condition of your brakes and brake pads? For sure, rainwater can get into these pads (5). Over time, moisture causes these brake pads to rust and squeak unexpectedly. It can also make your brakes less effective. Obviously, it is a severe safety concern.

Worn-out Rubber Bushings

Suppose you drive a car with worn-out rubber bushings. In that case, it can also cause unusual noises like clunks, rattles, or squeaking sounds from its undercarriage. It may appear more when you drive over uneven surfaces (10, 11). Likewise, these bushings act as shock absorbers between moving parts. However, they can squeak when wet due to reduced lubrication and increased friction.

The worn bushing may lead to steering control problems and stress on car joints. It may even damage the vehicle when its components snap. Additionally, they can cause premature wear of the tire. As a result, it can be costly to repair and replace. Other related problems due to worn-out bushings include excessive bouncing, poor handling, and additional stress on the connected parts (12).

Worn Out Ball Joints

When you drive a car in the rain, it may irritate you with clunking or knocking noises due to worn-out ball joints. You may possibly hear the noises from the vehicle’s front or rear suspension. It happens especially when the suspension moves up and down or when driving over uneven roads (13,14).

Squeaking may become stronger when you hit a speed bump during rain or travel on difficult terrain. Consequently, some symptoms of damaged ball joints are loose and shaky steering and a popping noise when taking slow or sharp turns. Sometimes, you may even feel vibrations through the seat, steering wheel, or brake pedal beside the noise (15).

Faulty or Worn Struts

Struts absorb shocks and keep the car stable. But, they can cause squeaks from internal components affected by moisture due to rain. Well, the sound may feel like a drum kit missing a beat, especially when driving over bumps or turning.

You will experience the car’s height sloped to one side. Also, the suspension may be more bouncy than usual (16). Some other signs besides squeaking noise include a noticeable decrease in ride comfort. Again, unusual tire wear and leaking fluid on the exterior of shocks or struts can indicate that the struts are worn out.

Lack of Lubrication

Lubrication keeps the moving parts functional to drive the car smoothly. But the rain may wash away some of the lubricants on the car. In this way, it can cause squeaking and squealing noises. Assume you do not lubricate the parts correctly. In that case, they can rub against each other, which is why there are unusual noises (5).

How to Diagnose & Fix Car Squeaks When It Rains

So, you can see noise from cars during (or after) rain, which can indicate multiple issues in your vehicle. You should diagnose them and fix them soon to avoid further problems.

Diagnosing Car Noises

Identify the noiseAsk yourself a few questions: Is it a new noise?Is it a lack of the usual noise?Is it a rattle, a grind, a squeal, or something else?  
Rotational noise or notYou can determine the problem lies with the rotating component if the noise has a cadence or timing that matches the rotational motion of some parts of the car.
Noise tied to engine or vehicle speedAgain, ask another question: Is it connected to the engine speed or vehicle speed? If the noise matches the vehicle’s speed while driving, issues may lie in the suspension, chassis, or wheels. Noise reaching engine speed, you can inspect under the hood.
Look for witness marksFind out if there are: Worn-off paintA slightly polished finishOil where it shouldn’t beA small amount of metal shavings
Use other waysUse your senses. For instance, I suggest smelling the odor. Failing brakes have a distinct smell, and a slipping belt could have a burning rubber odor.

Fix Squeaky Car Noises

Once you diagnose the issue, you can start fixing the problem. There will be no more squeaking noises from cars when it rains.

Replace or adjust beltsReplace the worn-out, cracked serpentine belt soon. If it is loose, you can tighten it using the tensioner.
Check and fill power steering fluidFill the fluid if it is low. If you find it contaminated, flush it out and refill it properly. For a defective pump, I suggest you replace it.
Replace worn brake padsReplace the damaged brake pads. Do not unnecessarily choose cheap ones, as they may be naturally squeaky.
Inspect and replace tiresUneven tire wires can sometimes cause squeaking. In this case, you need an alignment or replacement of the tires.
Lubricate the suspensionLubricate all the suspension parts regularly. It will reduce friction between those parts and eliminate the chance of squeaking during rain.
Professional helpIf all the fixes fail, you can call the mechanic. They will diagnose and solve the problem properly.

Final Words (with Suggestions)

Why does my car squeak when it rains? Are you still thinking about it? I hope you have understood the reasons well. Now, let me recap the blog.

Of course, the sound of raindrops hitting the roof of a car is soothing and relaxing. Also, heavy rain and thunder sounds can be heard when inside a vehicle during a storm. In this sense, noises are normal. But if it is from the car itself, then you may get a bit worried. It may indicate the issues I have already mentioned.

If you want to fix the squeaky car, you may think, “How much does it cost to fix a squeaky car?” Well, the cost of repairing a squeaking vehicle can vary depending on the issue.

  • Replacing a serpentine belt, a common cause of squeaking can cost between $80 and $200 (17, 18).
  • If the squeaking is due to a worn suspension, the cost could be significantly higher. It may range from $800 to $900 (17).
  • Brake pad replacement can cost between $115 and $300 per axle (17).
  • In some cases, like a wheel bearing repair, the cost can be as high as £262.56 (approximately $350) (19).

For more precise ideas, I suggest you check mechanic stores. They will give you the contemporary costs of fixing a squeaky car.

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