Why Does My Car Shake At High Speed? Causes And Solutions

why does my car shake at high speed

If the car shakes while you are driving at high speeds, it could cause concern and thus needs investigation. This article will diagnose why your car shakes at highway speeds so that you know when to raise the alarm and prevent other components of the car from getting damaged.

Car vibration while at high speeds is a common problem experienced by most drivers. Of course, most drivers end up questioning, "why does my car shake at high speed?" However, this can cause worry, since, for a car to shake, it could be due to the rotation of the crankshaft, transmission of gears and some moving parts of your engine.

How Can You Check For Car Vibrations?

But first, how can you check for car vibrations to see if they can cause a problem? Let us get into the article to learn more.

The most common reasons for car shaking are tire wear, misaligned wheels, brakes, suspension, or engine power. Sometimes, driving at high speeds could cause car vibrations that aren't related to the car components.

To be on the safe side, you need to determine the direction of the vibrations and the time they start.

For example, do the vibrations only start when you drive at high speeds? Do they happen when you start the car? Or do they happen when you use the brake pedal? Does your car squeak or rattle upon engine ignition?

After knowing when the shaking starts, you can diagnose the reasons that may lead to its shaking. Some of the major reasons that could cause your car to shake include:

  • Unbalanced Tires
  • Faulty Brakes System
  • Dirty Spark Plugs
  • Loose Lug Nuts
  • Bad Wheel Alignment

1. Unbalanced Tires

salvador, bahia / brazil - june 27, 2020: empty tire is seen in an abandoned vehicle in a condominium in the city of Salvador.

A common reason for a car shaking at high speed is unbalanced tires. Unbalanced tires do not only cause the car to shake at high speeds but also at low speeds. When a car is on low speed, an unbalanced tire may cause slight vibration, but when the car is on high speed, the vibrations are likely to increase.

Unbalanced tires often have a cupped wear pattern with a heavier section than the other.

Tire wear concept. Danger of using old car bald tire with very little tread remaining.

So, when you hit a pothole or bridge expansion joint, it results in out-of-balance tires that could knock off the wheel's weight, causing a sidewall bubble or dent the rims of your car. If your rims end up with dents, you can use the best chrome spray for rims that will give them a beautiful finish.

When the tire is damaged, the car vibrates from the steering wheel through the seat and floor. In most cases, If you feel the car vibrate from the steering wheel, it means the impact has affected the front tires, while when the car vibrates through the seat, it means the issue is with the back tires.

If you experience car sharing due to unbalanced tires, do not balance the wheels by yourself at home; instead, seek a mechanic as the process usually requires a wheel balancing machine.

Seeking help from a mechanic is crucial since he/she measures the imbalance and determines the number of additional weights you need to correct the problem.

2. Faulty Brakes System

car mechanic shows faulty brakes to customer

After the tires, the next place to check is your brakes. Brakes have three parts to check, including:

  • Brake rotors
  • Brake calipers
  • Brake drums

A). Brake Rotors

Brake rotors vary in thickness; this condition is known as excessive runout or being run out of round. When you experience excessive runout, your car vibrates when you brake. You can also feel the car vibrations each time you press on the brake pedals.

This condition can be due to the brake pads enduring heavy wear and tear; in other words, they could be overheated from heavier stopping than the brake disc can handle. To avoid this, invest in the best Detroit axle rotors and get quality out of your braking system.

B). Brake Calipers

Sometimes the issue could be that the brake calipers are stuck onto the brake discs. In this case, you will notice the car vibrating when you drive at higher speeds than 70 km/h and when you stop, you are likely to smell burning. To stop this, you should seek a brake caliper service to avoid further damage.

While you are at it, you can also revamp your brake calipers with a new color using the best paint for brake calipers on the market.

C). Brake Drums

Brake drums can be out of round in the same case as brake discs. When you press the brake pedal and feel your car vibrate, it is time to check the brake drums.

3. Dirty Spark Plugs

Man checks the spark plug on the old car

When your spark plugs are dirty or fouled, it may lead to car vibration while driving at high speeds. In addition, dirty spark plugs could lead to an engine misfire which in turn causes the car to shake.

Therefore, it's best to change the spark plug after a long time of use. You should remove both spark plugs and clean them or if they need replacing, replace them. If you remove one spark plug and it looks okay, remove the other one too since there could be a chance that there are oil leaks on the spark plug wells or the other spark plug is dirty.

4. Loose Lug Nuts

A mechanic tightening the lug nuts of a wheel with a torque wrench

Loose lug nuts can cause a minor to severe wheel wobble that may shake the car. If you fail to tighten the wheel lug nuts on time, they can become loose and even fall off. Loose lug nuts could cause a catastrophe and lead to collisions on the road.

After tightening your car wheels, do a crosscheck on the lug nuts before you start driving at a high speed to prevent this from happening. Ensure you use the correct size of lug nuts in tightening so that they do not become loose with time.

You can use a torque wrench to tighten the ball joints per the manufacturer's specifications.

Car mechanic hand using cross wrench to uninstallation the wheel nuts for changing alloy wheel of car in vehicle repair shop.

Again, while tightening the lug nuts, ensure you do not overlock them so that it will be easy for you to remove them next time.

5. Bad Wheel Alignment

Automobile low - Wheel Alignment

Poor wheel alignment can also cause your car to shake when driving at highway speeds. Wheel alignment is an important aspect while you are running checkups on your car's maintenance. Potholes and curbs are known to misalign wheels, thus resulting in poor control and rapid tire wear.

The most common symptom of misaligned wheels is your car moving to one side, and you have to adjust the steering wheel to drive in a straight line. Other signs include:

  • Uneven tire wear.
  • Crooked steering system components.
  • Bad wheel bearing.

Bad wheel bearings are a common reason why your steering wheel shakes; for this, you have to seek professional wheel alignment so that they check for issues such as tire pressure, tire rotation, and wheel balance to prevent your car from shaking.

Checking tire pressure with pressure gauge