Thumping Noise When Driving: Why It Happens and Solutions

Thumping noise when driving can be scary, especially if you don’t know the exact cause or source of the disturbing sound. It leaves you worrying whether the thumping sound is indicative or a major or minor issue, and rightly so.

This is because several factors can cause the noise and they range from trivial issues to crucial ones. This article will discuss the most prevalent causes of the clunky noise and suggest ways to fix them.

Why Do You Hear a Thumping Noise When You Drive?

You hear a thumping or clunky noise when you drive because it could be your tire warning you that it needs replacement or the engine indicating it needs servicing. Thus, you need to find out the exact cause. The sound could be coming from anywhere inside and around the car.

Then based on the findings, you can take the necessary steps to rectify the situation. You should also identify the phase of driving during which you hear the sound. For example, do you hear the sound when you’re accelerating, decelerating or cruising? Answering this question will help you to pinpoint which part of the vehicle could be the culprit of that clunky noise.

– Tires Wearing Out Irregularly

Car tires could produce unsettling sounds when they wear out unevenly or when the tire belt is shifting. The sound could emanate from the tire rubbing against the wheel or the surface of the road. Driving with worn-out tires is quite risky as the tire are unable to have a proper grip on the road, thus they’re prone to skidding or braking slowly. You can test your tires if it is difficult for you to conclude whether they’re worn or are in prime condition.

To perform this test, put a coin between the major treads of the car tire and check to see if you can see the outer band of the coin. If you see it, then it means your treads are worn out and will need replacement. However, if you don’t see the coin’s outer band, then it means the tire is in good condition. Thus, you’ll have to look elsewhere to detect the source of that thumping sound.

– Metallic Parts of Underinflated Tires Hitting the Road

When your tires are underinflated or suffer a puncture, their metallic parts may come into contact with the road. This is where the car makes thump sound when driving slowly as metal grinds against gravel on the road.

Cars run on rims that are protected by inflated tires, thus if the tires deflate, the rims lose their protection and would grind against the surface of the road. This can result in an accident, so we recommend you don’t drive with a deflated tire.

– Car Suspension Suffering Wear and Tear

If the tires are in good condition, you should check the car’s suspension system to determine whether that is the source of the unnerving clunk. The system is designed to absorb energy from bumps on the road and to ensure that drivers can maintain stability on rough terrains. Due to the nature of its work, the suspension system suffers wear and tear, which can cause a clunky noise.

The struts and shocks of a vehicle have a rubber or metal mount that connects to the chassis of the vehicle. This mount moves up and down according to the nature of the road and prevents the shock or strut from rubbing against the chassis. However, if they wear out, it allows the shocks to grind against the chassis, leading to the thump sound from rear of car. Sometimes worn-out struts and shocks can also cause that pounding noise.

– Dilapidated CV Joint

Also known as constant velocity, joints are devices that connect the wheels to the axles and are found at each end of the driveshaft. The outer CV joins the wheels to the driveshaft while the inner CV connects the transmission to the drive shaft.

Therefore, when the CV wears out, the wheels may come in contact with the axles, which will produce a screeching sound. The same thing applies to the wheel and the driveshaft.

– Transmission Mount Suffering Damages

If the noise comes from the front end of the motor whenever you accelerate, then it probably is the starter motor mount or the transmission mount. The transmission mount’s job is to keep the transmission safe and improve the overall quality of the driving experience.

However, its position under the hood of the car means that it is subject to vibrations and oxidations. Sometimes it can suffer damage when the vehicle gets involved in an accident.

All these factors can generate uncomfortable clunking noises when you press down the accelerator. The noise comes about when the transmission comes into contact with other areas of the vehicle. However, if you check the transmission mount and find no issues, then the next place to check should be the brake discs.

– The Wearing of the Ball Joints

The ball joints attach the wheels and the suspension system so they can move together. When the ball begins to wear, the suspension system may rub against the wheels, causing a clunking, popping or cracking sound. You usually hear this sound when you’re driving on a bumpy road or when you drive over road bumps. The sound can also be heard when you apply the brakes.

– Faulty Spark Plugs Misfiring in the Engine

Spark plugs ignite the air/fuel mixture in an engine’s cylinder to produce enough power in a process known as combustion. All components involved in the combustion process, including the spark plugs, are programmed to ensure they work in tandem for the desired effect.

However, if the spark plugs miss their timing due to damage and the mixture self-ignites, this can cause a thumping sound in the engine. The sound may not be too loud but it’ll be loud enough to cause a scare.

– Damaged Brake Discs Grinding Against Other Car Parts

Warped brake rotors may rub against the metallic parts of the braking system and generate a pounding noise when you apply the brakes. The brake discs are the visible circular discs behind the wheel of a car.

They, along with brake pads, help to bring the car to a stop by clamping on the wheels of the car whenever you apply the brakes. This action causes a lot of friction, which wears out the brake discs especially if you’re fond of braking unnecessarily. This can be the cause of your car making thumping noises.

What Are the Ways To Fix Thumping Noise When Driving?

The ways to fix the thumping noise when driving include repairing worn out and underinflated tires, fixing your car’s suspension, repairing misfiring spark plugs, fixing the rotors and ball joints, or fixing the broken and worn-out constant velocity joints and transmission mount.

Some of the issues are easy to repair and can be done by you or a professional mechanic. However, some of the issues are technical and will require the expertise of a technician to avoid further endangering your vehicle.

– Repairing Worn Out and Underinflated Tires

The best way to fix worn-out tires is to replace them, because implementing a stop-gap measure can only worsen the situation. To replace the tires, put wheel wedges under the other good tires to prevent them from moving during the process. The next step is to remove the wheel cover and then raise your vehicle with the help of a jack. Use a lug wrench to unscrew the nuts by going counter-clockwise and then remove the affected tire.

Mount the new tire and tighten the nuts and you’re done. However, if your tire is underinflated, just go to the nearest auto shop for assistance. You can also do it yourself but make sure the tire is inflated according to the specifications in your car’s manual book. Overinflating your tire could cause loss of traction and might lead to an accident.

– Fixing the Suspension of a Car

Fixing the suspension can be a very tricky and laborious task even for the most experienced DIY customers. Thus, we recommend that you turn to a professional to help you out. Toying with the suspension can prove fatal and attempting any amateur “quick-fix” procedure may only make it worse. Usually, the mechanic may advise you to replace the entire suspension just to be on the safer side.

– Repairing Misfiring Spark Plugs

Worn-out spark plugs are irreparable and can only be replaced. Fortunately, replacing it can be done by anyone irrespective of their DIY skill level. First, open the hood of the vehicle and remove the plastic cover and the air cleaner assembly. The next step is to remove all the vacuum hoses and label them so you can reconnect them to their proper places later. Then pull up the locking tab near the ignition coil electrical connector and remove it.

Now, remove the connector from the ignition coil and disconnect the coil and boot assembly. Once you’re done, remove the spark plugs with a torque wrench or by hand by turning it counter-clockwise. Insert the new spark plugs and use a torque wrench to tighten them. Remember to reinstall the ignition coil, electrical connector, air cleaner and plastic cover.

– Fixing the Rotors and Ball Joints

To fix the ball joints, first unscrew the lug nuts and remove the tire, then take out the brake caliper. Next, detach the bracket and remove the outer wheel bearing before pulling out the rotor with your bare hands. At this juncture, you can replace the worn-out rotor with a new one and put everything back in place the same way you removed them. However, fixing the ball joints is a different ball game.

First, detach the wheel so that you can get access to the ball joint, then spray the bolts with a metal cleaner to rid them of all dirt and mud. Next, remove the ball joint, which can be tricky depending on the type of strut or shocks. Also, remember to check and replace all the bad wheel bearings as they may also contribute to the noise.

We suggest you consult your car’s manual for directions on how to go about it. Install the new ball joints and the problem of the pounding noise would be solved.

– Fixing Broken-down Constant Velocity Joints and Transmission Mount

Constant velocity joints and transmission mounts can only be replaced when they are faulty or generate those unsettling sounds. The constant velocity joint costs between $100 and $250, but labor can be quite expensive and can go as high as $1,000.

Fixing the transmission mount is cheaper compared to replacing constant velocity joints, with the parts costing between $255 to $283 while labor is between $106 and $134.

Conclusion

A thumping noise coming from your vehicle is not to be toyed with as it could indicate a serious problem.

Here is a summary of the potential causes and how to deal with them:

• Worn tires and deflated tires can cause a car thump noise as the wheel comes into contact with the road, and this can be solved by replacing them.
• Faulty car suspensions and worn-out CV joints could cause other metallic parts of the vehicle to rub against each other and cause a thumping sound under the car while driving.
• Bad spark plugs can miss their timing during the combustion process and this can generate a loud sound, thus they should be replaced as soon as possible.
• Broken rotors and ball joints could also generate clunky sounds from the car and should be replaced.
• Some of the repairs and replacements like fixing bad spark plugs can be done at home, but replacing a suspension system should be done by a professional.

Finally, be sure to have these issues fixed as soon as you notice them to avoid endangering the vehicle and other road users.