Whining Noise When Decelerating: Is It Dangerous?

You noticed a whining noise when decelerating; is it dangerous to continue driving?

Unusual whining noises when accelerating and decelerating or even starting the car can all be a warning sign of a part not working properly or being damaged.

That’s why people always have to check their pet car as soon as possible every time they hear them.

So what should you do when you hear that sound from your vehicle? We’ve got all the causes and solutions in this post. Let’s get started! 

Whining Noise When Decelerating: Common Causes And Solutions 

whining noise when decelerating
Whining Noise When Decelerating

As usual, some common causes that your car makes whining noise when decelerating include the noise from the water pump, bad fuel pump, a driveshaft issue, bad transmission fluid, lacking power, problematic tires, squealing brake, lackluster power steering, or some wear and tear in the engine pulley, belts, and accessories belt tensioner.

Noise From Water Pump

Your car makes a noise when it slows down mainly because of the water pump. Coolant must be delivered to the core by the water pump.

You might experience this issue with your car due to insufficient lubrication or overheating. Beside the noise, if you detect a scorching, burning odor, it can malfunction.


To properly address this issue, you can replace the outdated component with an original spare part of high quality.

Bad Fuel Pump

Your fuel pump may be to blame if you only hear a differential noise on deceleration.

A poor or malfunctioning fuel pump can contribute to a whining sound when a vehicle slows down owing to inadequate fuel pressure.

Also, issues with your driveline components or car’s engine might be the culprit if you hear this noise when moving quickly at high speeds.


If you encounter this difficulty, you should replace the worn-out element with an original replacement part from a nearby auto parts retailer.

Driveshaft Issue

When you hear the driveshaft noise when decelerating, its driveshaft joints and boots should be inspected. When fractured, loose, or worn, they frequently create odd noises.

Use a feeler gauge to check for excessive play between the two halves of the joint if you have an inspection mirror but you can’t see any binding or looseness there.

Once there is more than 0.13mm (0.005 inches) of gap when fully loosened, replace the joint.


The driveshaft boots must be changed if they are torn or broken. Remember to replace the driveshaft joints when you see that they are worn or loosened.

Remove one boot at a time, rotate it back and forth, and look at it from various angles in both rotational directions to check your U-joints for signs of wear.

Bad Transmission Fluid

Bad fluid is a common trigger of transmission noise when decelerating. As usual, the dipstick’s MIN and MAX lines represent the ideal level for most transmissions.

Verify the transmission fluid‘s condition by observing its appearance and smell and checking whether it has turned dark or brown (these colors indicate contamination or a leaking seal).

In general, it should be clear to pale yellow in hue.

Also, your gearbox may be overheating as a result of internal damage brought on by inadequate lubrication and low fluid levels.


Check the level of the transmission fluid. If it appears too low, add extra liquid until it is at the proper level (reach the MAX mark).

You should take your automobile to a qualified auto repair if it is pinkish-orange or reddish-brown in hue.

Not Enough Power

Your car makes whining noise when slowing down if it does not have enough power.

When your vehicle seems to be moving very slowly, the spark plugs may not be firing properly, which could be the cause.

Also, ensure no oil, carbon, or anything else deposits.

A weak crankshaft position sensor, a poor injector, a bad fuel injection, or timing chain tension could all contribute to this issue.


At this point, cleaning the spark plug will help you to solve the issue. If this doesn’t work, purchase a high-quality spark plug from a reliable brand and test its functions.

Also, relearning the crankshaft position sensor might help sometimes.

Tire Issues

transmission noise when decelerating
The Defective Tires

When you slow down, the defective tires may give off a constant whining sound. You can hear a whining noise if your tires are under or over-inflated. So it’s best to first check the pressure in your tires.

Your tires’ tread depth, wear pattern, balance, and alignment are the following things you should examine.

These elements may also play a role in this issue if the wheels are out of balance or if your alignment specs have excessive toe-in or toe-out (which results in uneven wear).


Check the tires and inflate them. The important thing you need to do is ensure the tires are balanced to eliminate this strange sound and ensure safety.

Brake Squeal

The brakes on cars often screech, but this is because they’re meant to alert you when it’s time for a replacement.

Manufacturers incorporated wear indicators that will begin squealing as the brakes need to be replaced because your pads are out of your regular line of sight.


Investing in new brake pads is advised, which is standard maintenance and entirely normal. You may have glazed pads if your brakes screech, but your brake pads aren’t worn out.

Glazing can happen when brake pads are overheated or contaminated before becoming hot.

Power Steering

Your power steering wheel and its system allow you to spin the wheel with little effort while exerting much force on the tires.

The hydraulic power pumps must be kept oiled because they provide a lot of force.

The differential noise when decelerating happens when the system leaks or other problems occur, causing the power steering fluid to drop.


It’s crucial to address these problems first; despite the possibility that the pump is the cause of the whining sounds, the leak’s source may be somewhere else.

Give the whole system an inspection to check all steering rack boots and seals. If these boots are damaged or absent, dirt and filth may enter the racks’ gearing and eventually wear down the teeth.

And when you decide to change the fluid, remember to choose the right type for your car, for example, specific power steering fluid for BMWs.

Engine Pulley

Many pulleys are connected to each of these auxiliary pumps and are rotated by the belt. Little bearings inside these pulleys ensure they can spin without leaving wear and tear.

These bearings may eventually wear out and produce a whining or grinding noise. The whining sound will worsen as the engine RPM rises.


To identify the rear end noise on deceleration issue, move from one pulley to another while running your car with the hood open.

Apply some lubricant to the pulley’s center, close to the bolts. You know what pulley is having problems when the whining or grinding stops.

These bearings are under a lot of pressure; therefore, you should replace them or the complete pump if necessary.

Engine Belts

These little belts, also known as accessory belts, rotate many accessories in the vehicle, like the alternator, air conditioner, water pump, and many more, using your engine’s power.

These belts may start to creak or wear out over time and eventually break down. With higher engine RPMs, this whining sound will get louder.

Never use your car without a belt since you can end up with long-term harm.


Spray-on lubrication can be used to test this noise. Apply a little spray oil on the belt while the car is running, and you can hear the squeak, then check for any changes.

Avoid spraying the other engine components to ensure the problem is with the belt. These belts should be replaced every 50,000 to 100,000 miles as routine maintenance.

Accessories Belt Tensioner

A tensioner keeps the belt taut as it passes by the accessory pulleys. This tensioner’s ability to function properly may diminish if dirt and filth get inside it.

As a result, the belt will be left hanging slack and may begin to slide over a pulley instead of keeping them all turning, groaning loudly. Over time, this slippage will result in severe belt wear.


Sometimes, the pivot point may make a whining or squeaking sound when flexing back and forth in a more erratic manner.

It can be cleaned and greased with a dry-spray lubricant to lessen the noise. And the best way is to replace it for better performance.

How To Diagnose The Issue? 

differential noise on deceleration
Way To Diagnose The Problem

How to diagnose the cause if you hear the motorcycle whining noise when decelerating?

The whining sound you notice as you slow down frequently results from an issue with your car’s brake pads, fuel pump, pulley belt, etc.

You may perform a few easy things to identify the problem once you have heard this noise and are unsure of what it is.

  • Look over your brakes to see whether they are worn out. This indicates that your brake pads may need to be replaced.
  • Look for symptoms of wear and tear in the vicinity of your wheels and tires. Watch for signs of uneven tire wear or minor rim damage, which could point to brake caliper or rotor issues.
  • Check your transmission fluid level.
  • The engine belt and pulley should be inspected.

In case you can’t detect any abnormalities with the naked eye, bring your car to the car service center and ask for help from the mechanic.


Can Low Transmission Fluid Cause Whining Noise?

Yes, as mentioned above!

These sounds are frequently louder, sharper, and clunkier when there is an automatic/manual gearbox issue.

The automatic transmission fluid is likely low when the car makes a whining or buzzing noise. In this situation, you should promptly refill that fluid.

What If My Car Makes Whining Noise When Turning?

There’s a significant probability that your power steering system is malfunctioning if your automobile makes a whining noise as you turn the wheel.

Checking for damage or looseness in your steering belt should be your first step.

If the belt is making noises, your power steering system’s fluid leak is the next most likely culprit.

If you check your fluid level and it is significantly lower than you would anticipate, this is probably where the whining comes from.

What Causes The Wheel Bearing Noise?

Top reasons that lead to the rear wheel bearing noise include:

  • Improper installation of the bad wheel bearing.
  • Water moistens the wheel bearing and causes the lubricant to lose its effectiveness.
  • Rough roads or strong impacts bring more heat and friction, polluting the lubricants.
  • Bad socks or unbalanced tires.
  • The accident near or on the wheel area.


If you notice the whining noise when decelerating, remember to diagnose the main cause as soon as possible. Delays can make the problem worse or take a toll on the related components.

The best way is to seek the help of experts, especially when you do not have too much knowledge or experience. They will deal with the problem faster and more efficiently, but it will cost you quite a bit.

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