5 Causes of Car Rattling When Going Over Bumps

car rattling bumps

Last updated: February 17, 2023 at 13:00 pm

It’s no surprise that cars make a fair amount of noise, and most of the time they’re supposed to make those noises.

Sometimes, though, they make noises that take us by surprise – like when they rattle as we go over bumps. But what causes those noises, and is there a way to stop them?

5 Reasons a Car Rattles When Going Over Bumps

1. Ball Joints

ball joint

Ball joints are critical elements of a car, they connect your wheel hubs to the control arms, providing the vehicle with pivoting movements to give you and the car a smooth ride.

Without them, you would not be able to control your vehicle at all. When these ball joints begin to develop issues, they can cause a rattling noise within your car as you go over bumps.

Typically this noise is caused by worn ball joints that become loose, allowing the suspension to rattle around. When you go over bumps, or when you speed up, this will then cause a vibrating or rumbling sound in the cabin of the car.

To check to see if your ball joint is the cause of the problem, raise your car on a jack and jack stands. Shake the wheel between the 12 o’clock and 6 o’clock position. If the ball joint is moving, then it’s likely to be the cause of the problem. You can also squeeze a ball joint with pliers and watch for play or prying it upwards and checking for play.

Is it fixable?

If you catch the worn ball joint early enough, before it becomes a safety hazard, you might find that you can repair it or pay for a mechanic to do so. Usually, though, by the time it has started rattling, you’ll find that you’ll need to just replace the ball joint.

Fortunately, these parts are not too expensive, and most mechanics can replace them quickly.

2. Strut or Strut Bushing

Struts, just like shocks, are an essential part of the car’s suspension system. They help to ensure you have a smooth ride and that steering, stopping and stability are all maintained from start to finish. They also help to prevent other elements of suspension and even the tires from wearing out.

Inevitably, though, these elements do eventually wear out themselves. When this happens, you might notice a rattling noise beneath your car when you go over bumps, and you may also experience tire wear, reduced braking efficiency, and a loss of handling in control. You may also notice noises coming from elsewhere in your vehicle due to increased wear on suspension parts.

You can check to see if your car has bad struts by putting your car on a jack and having someone press down on the car hood to mimic bouncing. As they do so, locate the coil spring and listen for the rattling noise. If you hear it near the strut, particularly near the top of the strut, then that’s likely the culprit.

Is it fixable?

Unfortunately, not all car struts cannot be repaired. Some struts have replaceable cartridges, meaning that they are repairable.

Otherwise, upon establishing that your car is suffering from worn struts or strut bushings, you will need to replace the element.

3. Worn Tie Rods

tie rod

Tie rods are essential for a car’s steering. They have an inner and outer end, both of which can wear. Alongside the ball joint they convert force from the steering center and help to properly align the front end of the vehicle. Just as with any other element, tie rods often wear down over time. This can lead to movement, which then creates a vibration and a rattling noise. This noise will likely be most prominent when going over bumps or around corners.

Here’s how to check to see if tie rods are causing your car to rattle when you go over bumps. Raise the vehicle with a jack and jack stands and carefully shake the tire side-to-side, moving it from the 3 and 9 o’clock position. If there’s any movement on the tie rods, then you’ve found your problem!

Is it fixable?

If your tie rods are worn, it’s time to replace them. Not much can be done in terms of working to repair tie rods, so it’s easier (and safer) to just take the worn ones out and replace them completely.

4. Control Arm Bushing

Bushings are made from rubber, so they wear easily over time. They regularly tear and crack from the amount of impact absorption that they do on a regular basis. This is especially common in cars used for off-road adventures.

When they become worn, the control arm will then begin to cause strange noises – including rattling – as you go over bumps or potholes. You might also find that your vehicle has become harder to control.

You can check on your control arm bushings by nudging the end of the control arm and watching to see if it moves. If you hear a noise or see movement, you’ve found the culprit.

You should also check the control arm bushings for any evidence or signs of dry rot or cracking. These, or rust, suggests that it is time to replace the bad control arm bushing.

Is it fixable?

Since control arm bushings are rubber, when they are worn, they must be replaced. Failing to replace them can lead to a safety hazard as worn bushings can cause premature tire wear and issues with suspension.

5. Sway Bar Links

Sway bars are part of the suspension system, and they reduce the vehicle’s sway. They are not found in every vehicle, but they are often found in larger vehicles and can come loose or worn. When this happens, as with many elements of the suspension system, there will be a rattling noise as you go over bumps.

To check for bad sway bar links, you can grab the end of the sway bar link and wiggle it. If you hear a noise, it will need replacing.

Is it fixable?

Unfortunately, worn sway bar links – or stabiliser links – must be replaced. They cannot be repaired and can cause your vehicle to become harder to manage so should be replaced quickly after you spot the issue.

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About the Author: AJ

AJ is a self-confessed soundproofing nut. He has written full-time on Quiet Living for the past 4 years, and has a wealth of knowledge about living a quieter life, soundproofing and fixing loud noises.

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