Why Does My Car Shakes When Accelerating [But Not When Coasting]

The pleasure of having a good-functioning car is underrated. Any issue with the vehicle can cause a bad driving experience for the driver. After some period of usage, it is normal for the vehicle to shake due to wear and tear. However, the car shaking during acceleration but not when coasting is an indication that there is a problem.

Different things can cause the car to shake during acceleration but not when coasting. The reasons range from a defective component of the vehicle or leakage in a part of the car.

A car is only as good as when all components function well. Therefore, checking for the problem when it is noticed is vital to avoid it leading to further issues. There are many reasons why a car shakes when accelerating but not when coasting. Below are some of the reasons.

10 Reasons Why Your Car Shakes During Acceleration But Not When Coasting

1. Bad CV Joints

car shakes when accelerating but not when coasting

A car transmission system consists of a constant velocity (CV) joint, which is a small part of the system. It is located in the front wheel drives of most cars. It works by enabling power to be transmitted from different places by the vehicle’s drive shaft.

A car has two CV joints, namely the outer and inner CVs. Consistent car usage leads to wear and tear, which can affect these joints and make them go bad. Also, cars that carry heavy loads and passengers more than the normal capacity may experience a bad CV. Wear and tear can also damage the CV joint boot making it accumulate dirt over time. The accumulated dirt then causes damage to the metal parts due to friction.

Consequences of a Bad CV Joint

A bad CV joint can cause the car to shake when accelerating. Some drivers also say their cars vibrate whenever the CV joint is bad. As time goes on, the vibrations worsen, leading to more serious problems.

The Solution to a Bad CV Joint

A car user should see the mechanic immediately if there is a problem with the CV joints. Most times, a replacement of the CV joint boot is the solution to a faulty one. Therefore, the mechanic should run a proper diagnostic test to ascertain that the problem is from the CV joint.

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2. Bad Struts

car shakes when accelerating but not when coasting

Car struts work similarly to the suspension system of a vehicle. It is a system of two major elements that carry the vehicle’s weight. It consists of the coil spring, which acts as the supporter, and the shock absorber, which cushions the effects of road bumps.

Consequences of a Bad Strut

As a result of constant usage, it is common for the struts to crack. In worst cases, the struts can break. When this happens, the car begins to shake during acceleration. The shaking is due to the inability of the support system to work properly.

The solution to a Bad Strut

Bad struts can lead to accidents. Therefore, it is important to replace a bad one immediately to avoid accidents and other problems. A trained mechanic mostly does the replacement because of the peculiarity of the component.

3. Unstable Tires

car shakes when accelerating but not when coasting

It is common for tires to be unstable or unbalanced, especially after being newly installed. The imbalance results from the tire’s weight being unevenly distributed.

Consequences of Unstable Tires

Unbalanced tires can affect the comfort of the ride. With time, the situation can worsen, and the vehicle begins to shake. In addition, the wheels and the car suspension can go bad due to this problem.

The Solution to Unstable Tires

Unstable tires can make the driver have a bad driving experience. Therefore, it is good that the driver ensures that the car tires are balanced. Most mechanic shops balance tires at a cheap rate. Some others do it for free alongside other servicing the car needs.

4. Worn-out Brake Calipers

why does my car shake when i accelerate

The brake caliper is an essential part of the vehicle. It contains brake pads and pistons. It creates friction when the brake is engaged, which in turn slows down the car. In other words, it works on the brake rotors by clamping them down, preventing the wheel’s turning.

With time, the brake calipers can go bad and wear out. One of the brake calipers components can also go bad and extend its damage to the calipers.

Consequences of Worn-out Brake Calipers

Worn-out or bad brake calipers cause a reduction in the braking ability of the vehicle. The bad brake calipers may make the car vibrate or shake when accelerating or driving.

The Solution to Worn-out Brake Calipers

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The main solution to worn-out calipers is a replacement. You can also see the mechanic rebuild the calipers. However, replacing the bad ones is the best solution.

5. Worn-out Engine Mounts

why does my car shake when accelerating

The engine mount is the part of the vehicle that holds the engine in place. A car has about three mounts. One holds the transmission, and the other holds the engine. Also, the mounts keep the engine vibration in check so that it will be manageable. It helps to reduce the vibration during driving to the barest minimum.

Although the engine mounts do not require regular maintenance, they can still go bad. They might experience wear and tear after some years and become bad.

Consequences of Bad Engine Mounts

As a result of wear and tear, the engine mount may experience an inability to work well. The engine shifts and becomes unstable, leading to the car shaking. Also, the engine may produce some unpleasant sounds. These sounds come from the contact between the frame of the car and the hood. In worst cases, all the car occupants experience the car shaking, leading to an unpleasant driving experience.

The Solution to a Bad Engine Mounts

Replacement of the engine mounts is important when there is a problem with them. The replacement is crucial because bad engine mounts can affect the engine and the whole vehicle.

6. Bent Axle

Why Does My Car Shakes When Accelerating

Like other car parts, the axle is also a crucial part of a vehicle. The axle consists of a rod connecting the wheels and moving them when accelerating. The axle rotates the wheel through the force supplied by the engine for the car to move forward. Therefore, when the axle spins, the wheels move the car in the direction you want.

The axle is made to be strong and flexible. Therefore, the axle can withstand some pressure. However, the axle can become bent or damaged when the pressure is too much. When this happens, the vehicle begins to strain when propelled to move forward and can shake or vibrate.

Consequences of a Bent Axle

A bent axle can result in brake problems and misalignment. The brake pads may misalign with the rotors, making the vehicle vibrate when applied. In the worst cases, the wheels and the braking system will stop functioning.

The Solution to a Bent Axle

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It is rare for a bent axle to be straightened or fixed. The replacement of the axle is often the solution to a bent one. The metal of the bent one is already weakened, and fixing it on makes the axle last long. Therefore, total replacement is the best option.

7. Faulty or Dark Spark Plugs

car shakes when accelerating but not when coasting

The car plugs work by sparking up electricity whenever there is a need to start the car. The plug ignites the combustion by emitting electricity that will put the air-fuel mixture to work and make your vehicle move

The spark plugs need proper maintenance like every other part of a vehicle. With constant usage, the spark plugs may experience inbuilt dirt over them and become black. When this happens, the spark plug begins to malfunction.

Consequences of a Dark Spark Plug

The dark spark plug is full of dirt and debris, thereby making the part unable to function well. The plugs will be unable to combust well and affect the vehicle when accelerating. This problem can cause slow or no acceleration or shaking of the car when acceleration finally occurs.

The Solution to a Dark Spark Plug

Replacing the spark plug is the main solution to the problem. Fortunately, it is easy to replace the plugs without visiting the mechanic.

8. Loose Lug Nuts

car shakes when accelerating but not when coasting

Lug Nuts are fasteners used to fasten the wheel’s hub to the car’s axle. It is normally placed on the wheel stud to secure it in place. Also, the nuts are part of the essential parts of the suspension system of the vehicle. They come in different shapes and sizes depending on the type of vehicle they are working with.

After working for some time, the nuts can get loose. Some of the nuts are not properly tightened initially making them feel loose over time.

Consequences of Loose Lug Nuts

When the lug nuts are loose, they will be unable to tighten the wheel’s hub to the vehicle axle. Also, the car shakes when accelerating but not coasting when the nuts are not properly fastened. Moreover, the loose nuts can affect the wheels and the rotor. In worst cases, the wheels can go out by themselves while driving.

The Solution to Loose Lug Nuts

You can tighten a loose nut without the help of a mechanic. However, if the lug itself is loose or has a problem, it needs replacement.

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9. Worn Out Clutch

Car Shakes When Accelerating

The car’s clutch works by increasing or decreasing the vehicle’s speed when the need arises. It does this by disconnecting the engine of the car from the wheels while the vehicle’s ignition is still on. As a result, the engine that is working does not affect the wheels.

The clutch is also responsible for moving the car from one place to another. It does this by working with the transmission processes and flywheel of the car. Unfortunately, the clutch can wear out due to friction after prolonged usage.

Consequences of Worn-Out Clutch

A worn-out clutch can make the car shake when accelerating but not coasting. Also, the clutch will be unable to transmit the normal torque amount to the flywheel for the car to move. Therefore, it will take more time for the vehicle to accelerate and experience shaking.

The Solution to Worn-out Clutch

You can repair a worn-out clutch. Also, you can replace it. Fortunately, the replacement can be done at home with or without the presence of a technician.

10. Vacuum Leakage

car shakes when accelerating but not when coasting

A vacuum leak in an automobile is when there is a quantity of air outside the normal passage for air. When this happens, there will be a reduction in the fuel-air mixture required for the engine to function properly. A crack in the intake hose is majorly the cause of vacuum leaks in cars.

Consequences of a Vacuum Leakage

A vacuum leak causes a loss of power to the car engine. A leak shows that one of the hoses has been damaged. In the worst cases, it affects the car’s transmission system and causes it to shake while accelerating.

The Solution to Vacuum Leakage

The cause of a vacuum leak is challenging to find. The auto repair technician is responsible for checking where the leakages are occurring. Different methods are used in the diagnosis of a leakage in the vehicle.

Frequently Asked Questions

Can Low Oil Cause Car Shake When Accelerating?

Low engine oil can make the car shake when accelerating. It is one of the major signs that there is insufficient oil in the car.

Engine oil plays a major role in lubricating the engine. As a result of this, the engine and its components are well-lubricated and free from friction. However, when there is low oil, the engine starts to shake and vibrate due to friction. At this stage, the main solution is to top up the oil of the car.

Why Car Vibrates When Accelerating at Low Speed?

A bent or damaged axle can make the car vibrate when accelerating at low speed. The axle is an important part of the vehicle. It spins and helps the wheel to move the car in the direction that you want. If the axle is bent or damaged, the car can vibrate when accelerating at low speed. When the car accelerates faster, the vibration worsens. 

What to do if Your Car Shakes When Accelerating? 

Car shaking when accelerating could be a result of different things. The source of the shaking can range from loose lug nuts and imbalanced tires to dark spark plugs and others. You should see an auto repair technician to diagnose the problem when your car shakes when accelerating.

Can a New Tire Installation Cause My Car to Shake?

New tires that are not properly fixed can be unbalanced and cause the vehicle to shake.

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It is common for car users to experience shaking when the vehicle is accelerating. When this happens, it is usually due to a problem with one of the car’s components.

Therefore, it is important that an auto mechanic runs a proper diagnostic test on the vehicle. The test will show the problematic area, and a replacement or repair will make the vehicle work well again.  

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