Top 8 Reasons For Car Shaking While Driving (+Diagnosis)

Let’s be honest.
No matter how loud you play your music, you can’t ignore a car shaking while driving.

Several mechanical issues can cause a car to shake, some being quite dangerous and needing urgent resolution.

So, let’s cut to the chase.
We’ll go through the reasons for car shaking; then look at how to diagnose it. As a bonus, we’ll also answer some car shaking FAQs, including whether driving in that condition is safe.

This Article Contains:

8 Reasons Your Car Is Shaking While Driving
How To Diagnose A Shaking Car
3 FAQs About Cars Shaking While Driving

Let’s begin.

8 Reasons Your Car Is Shaking While Driving

Here are the eight most common causes of car shaking:

1. Wheel Issues

Car shaking while driving is almost always linked to wheel troubles. The cause can be the wheels and rims, a faulty wheel alignment, or a worn wheel bearing.
Let’s cover each in detail:

A. Damaged Tires Or Rims

Maybe you’ve had a minor accident, scraped a curb, or are overdue for a new tire set.

Uneven tire wear or tire damage (formation of cracks or bubbles) can affect tire integrity. If ignored, a tire issue can lead to a bumpy ride and affect drivability.

B. Improper Wheel Alignment

If you have misaligned wheels, they’ll fight each other to find the correct wheel angles while driving — causing some strong wheel vibration and car shaking.

Moreover, components like a wheel ball joint and bushings wear over time, and start giving “play” in your wheels when you move the steering wheel. If you notice diminished steering performance or experience a shaky steering wheel (steering wheel vibration), you should get the unbalanced wheel fixed urgently.

C. Worn Wheel Bearing

Wheel bearings allow the wheels to rotate freely while connected to the axle.

When a wheel bearing is worn or damaged, the respective wheel can start moving in and out. This causes resistance between the wheel and the axle, resulting in wheel vibration when the car is at highway speed.

2. Brake Problems

The only thing worse than brakes that don’t work are brakes that work when they shouldn’t!

If you hit the brake pedal and your car vibrates, the likely culprit is a faulty brake rotor (brake disc) or brake caliper. A defective brake caliper or rotor will cause the brakes to always be slightly applied while driving (even if the brake pedal isn’t engaged), leading to a strong car vibration.

3. Engine Problems

Here are the two possible reasons your engine is causing a car vibration:

A. Worn Motor Mounts

Motor mounts (engine mounts) rest between the engine and the engine bay to prevent engine vibration from traveling through the car’s body.

If a motor mount deteriorates, you’ll be able to feel vibrations from the engine whenever it’s running. The more power the engine exerts, the more vibration you’ll feel.

B. Worn Spark Plugs

If your spark plugs have outlived their use, they’ll tamper with your engine’s piston firing order.

This new firing order can cause misfires, creating a shake in the engine with each firing cycle. A quick spark plug replacement should do the trick. If not, check your air and fuel filters.

Why?
A clogged air or fuel filter can starve the spark plugs of both ingredients needed for combustion. Less air or fuel causes misfires and engine shaking, too. When that happens, your Check Engine Light will come on.

4. Bent Axle And Driveshaft

A recent fender bender could have bent your axle. A bent axle can lead to shaking between 40-50 mph, with the vibrating increasing along with speed.

On the other hand, bent driveshafts cause shaking at lower speeds, which fluctuates based on acceleration and braking.

If your axle and driveshaft pass inspection, the cause might be a worn CV joint.
A CV joint is a rubber casing that rests around each end of the axle. When these wear down, they allow a strong vibration to move up into the car’s body.

5. Damaged Steering Column

A fully functioning steering column (the connection between a steering wheel and steering mechanism) is essential for your car’s drivability. However, some components within may wear out over time, creating a play in the bushings and the ball joint. This can lead to vibration in the steering wheel.

If you notice a sudden steering wheel vibration or a shaky steering wheel, take the hint!
Get the steering column checked ASAP.

6. Power Steering Issues

You’ll know power steering issues are at fault if you only notice car vibrations during turns. Check for power steering fluid leaks.

7. Faulty Suspension

Your suspension could be the cause of car vibrations if:

It’s out of alignment
It has loose components, such as shocks or struts
Certain parts are damaged, like a worn tie rod

If you suspect that your suspension may need some TLC, get a diagnostic to be sure.

8. Low Transmission Fluid

Transmission fluid lubricates moving metal parts and bearings in the gearbox. It also helps create hydraulic pressure where needed.

Low transmission fluid levels can cause some grinding, which translates into shaking in the car when you try to accelerate. If you notice a transmission fluid leak, ensure that your next stop is the mechanic for a transmission repair.

Now that you know the causes of car shaking, we’ll go over how to diagnose them.

How To Diagnose A Shaking Car

There are five primary inspections to diagnose car shaking.
Here’s what a mechanic usually does:

1. Inspect And Balance The Tires

They’ll inspect the tires and rims for visible damage or uneven tire wear. If there’s a tire issue like bubbles or bends in the rims, they may suggest getting a new tire.

If there’s no tire wear, they’ll use a tire balancing machine to fix misaligned wheels. Sometimes, a simple tire rotation may also fix the issue.

2. Inspect The Brake Rotors

They’ll inspect the brake rotors for rust and check for a warped brake rotor. A warped rotor should always be replaced.

They may also do a test drive to see if the shaking occurs while hitting the brake pedal. More aggressive shakes while braking is cause for further inspection. Shaking felt in the steering wheel indicates problems with the front brake rotors. Any shaking elsewhere means the rear brake rotors are at fault.

If there’s no shaking during braking, the mechanic may suggest an engine diagnosis.

3. Engine Inspection

The first indicator for an engine issue is an illuminated Check Engine Light. If it’s on, three engine components need assessment: spark plugs, motor mounts, and transmission fluid.

Here’s what the mechanic will do for each:

Spark plugs: Each spark plug is removed and checked for damage. If the spark plugs are sound, they’ll inspect the air and fuel filters.

Motor mounts: Since motor mounts are made of rubber, they’re almost always unrepairable. Any tears or cuts in the engine mounts mean it’s time for a new set.

Transmission fluid: If transmission fluid levels are low, a top-up of transmission fluid might resolve the shaking. Otherwise, they’ll check the transmission for leaks, and you may need a transmission repair.

If all other inspections are inconclusive, then a suspension inspection is warranted.

4. Suspension Inspection

They’ll inspect the tie rod, bushings, and other connecting components for damage. They’ll do this on both the front and rear suspension. They’ll also check the steering fluid level and look for possible leaks on the driveshaft, boots, and CV joints.

5. Driveshaft And Axle inspection

The final possibility for car vibrations is a faulty driveshaft or bent axle.

Damage or bends in the driveshaft could lead to intense vibrations throughout the car’s body. A mechanic will test drive the vehicle to see if the shaking occurs at constant speeds and visually inspect the driveshaft and axles for issues.

Damaged driveshafts usually require replacement instead repairs.

Now let’s explore some car-shaking FAQs.

3 FAQs About Cars Shaking While Driving

Here are the answers to some car-shaking questions:

1. Is It Safe To Drive A Shaking Car?

Short answer — no.

While all cars shake mildly when driving, aggressive shaking is a sign that something’s wrong with your car. It could be hazardous if specific components (like the brake rotors or engine) become faulty.

Get your car assessed ASAP if you notice strong vibrations or shaking while driving.

2. Why Does My Car Shake At Higher Speeds?

If your car shakes at high speed, your wheel bearings are likely worn, or you might have damaged tires and rims. Stay safe and get your wheels inspected — especially if you’ve recently hit a curb or had a mild fender bender.

3. Why Does My Car Vibrate At Idle, But Smooth Out At Speed?

If your car shakes when stationary but smooths out as you gain speed, your motor mounts are likely bad.

Motor mounts absorb engine vibrations but transfer this shaking to the car’s body when worn. This is quite noticeable at idle or low speed. However, your engine is better supported when driving at high speed, reducing the vibrations felt.

Wrapping Up

Car shaking while driving is not only uncomfortable but also problematic, as it indicates that something in your vehicle isn’t working right. But solving the issue doesn’t have to be hard.

Get help from a trusted mechanic like RepairSmith.

RepairSmith is a convenient mobile vehicle auto repair and maintenance solution with expert mechanics who’ll fix the problem right in your driveway. We offer competitive, upfront pricing, and online booking is easy.