If your car shakes or vibrates when you accelerate, don’t ignore the problem. A vehicle that runs smoothly at idle but shakes under acceleration may have an issue with the engine, drivetrain, tires, suspension, or another component.
Some causes are relatively inexpensive to repair, while others can become costly if ignored.
In this guide, we’ll explain the most common reasons a car shakes when accelerating and what you should do about them.
1. Worn or Damaged Engine Mounts
Engine mounts hold the engine securely to the vehicle while reducing vibration.
When a mount becomes worn or breaks, the engine can move more than it should. You may notice increased vibration when accelerating, particularly at low speeds.
Other symptoms can include:
- Clunking noises
- Excessive engine movement
- Vibration while idling
- A noticeable thump when shifting gears
A mechanic can inspect the mounts for cracks, deterioration, or excessive movement.
2. Bad CV Axle or CV Joint
Front-wheel-drive and many all-wheel-drive vehicles use CV axles to transfer power from the transmission to the wheels.
A worn or damaged CV joint can cause vibration during acceleration.
You might also hear clicking or popping when turning, particularly if a CV joint has significant wear.
3. Tire Problems
Tires can cause vibration for several reasons.
Possible issues include:
- Tire imbalance
- Uneven tread wear
- A damaged tire
- A bent wheel
- Improper tire pressure
If the vibration is strongest at a particular road speed rather than specifically during acceleration, tires or wheels become especially worth investigating.
4. Wheel Alignment Problems
Poor wheel alignment can cause uneven tire wear and handling problems.
Although alignment problems don’t always directly cause acceleration-related shaking, they can contribute to vibration and unstable handling.
Look for symptoms such as:
- Vehicle pulling to one side
- Uneven tire wear
- Steering wheel not centered
- Poor handling
5. Worn Suspension Components
Suspension components such as control arms, bushings, ball joints, and other parts can wear over time.
Damaged suspension components may cause vibration, clunking, steering problems, or unusual tire wear.
Because suspension components affect vehicle control, serious problems should be inspected promptly.
6. Engine Misfire
An engine misfire is another possible cause.
If one or more cylinders aren’t combusting properly, the engine may run unevenly. The vibration may become more noticeable when accelerating because the engine is under greater load.
Possible causes of a misfire include:
- Worn spark plugs
- Ignition coil problems
- Fuel delivery issues
- Vacuum leaks
- Injector problems
- Other engine faults
A check-engine light may also appear.
If the check-engine light is flashing, reduce driving and have the vehicle inspected as soon as possible because continued operation can potentially damage the catalytic converter.
7. Fuel Delivery Problems
An engine needs the correct amount of fuel to operate properly.
Problems involving fuel injectors, fuel pressure, or other fuel-system components can cause hesitation, poor acceleration, and vibration.
Diagnosis may require professional testing rather than simply replacing parts.
8. Transmission Problems
A transmission problem can sometimes cause shaking during acceleration.
Depending on the vehicle, you might also notice:
- Harsh shifting
- Delayed engagement
- Slipping
- Unusual noises
- Difficulty changing gears
Transmission problems can vary considerably in severity, so early diagnosis can be valuable.
9. Driveshaft or Drivetrain Problems
Rear-wheel-drive and all-wheel-drive vehicles may have driveshafts, universal joints, differential components, or other drivetrain parts that can produce vibration under acceleration.
A vibration that appears specifically when applying power can be an important diagnostic clue.
10. Brake or Rotor Problems
Brake-related vibration is usually more noticeable while braking rather than accelerating.
However, if components are damaged or dragging, they can contribute to vibration and unusual vehicle behavior.
A brake inspection can help rule out brake-related causes.
When Is Shaking Dangerous?
Not every vibration means your vehicle is unsafe to drive.
However, you should take the problem seriously if you experience:
- Severe shaking
- Loss of power
- A flashing check-engine light
- Steering problems
- Loud mechanical noises
- Burning smells
- Difficulty controlling the vehicle
In these situations, stopping in a safe location and arranging professional assistance may be the safest option.
How Much Does It Cost to Fix a Shaking Car?
The repair cost depends entirely on the cause.
A tire balance may be relatively inexpensive, while replacing a CV axle, engine mount, suspension component, or transmission component can cost considerably more.
The best approach is to diagnose the cause before approving repairs.
Frequently Asked Questions
Why does my car shake only when I accelerate?
Acceleration places additional load on the engine and drivetrain. Problems with engine mounts, CV axles, drivetrain components, ignition, or fuel delivery can therefore become more noticeable during acceleration.
Why does my car shake at low speeds?
Low-speed shaking can have several causes, including engine mounts, CV joints, tires, suspension components, or engine performance problems.
Can bad spark plugs cause a car to shake?
Yes. Worn or faulty spark plugs can contribute to engine misfires, which may cause noticeable shaking, especially under acceleration.
Can low tire pressure cause shaking?
Incorrect tire pressure can affect handling and may contribute to vibration, but significant shaking should not automatically be blamed on tire pressure.
Final Thoughts
A car that shakes during acceleration can have anything from a relatively simple tire issue to a more serious engine or drivetrain problem.
Pay attention to when the shaking happens, whether it changes with speed, and whether other symptoms occur.
An accurate diagnosis is usually more valuable than replacing parts based only on symptoms.
