Understanding why your car shakes when accelerating
When your car vibrates or shakes while accelerating, it typically means that something is out of balance or not functioning properly in the drivetrain, wheel, or engine. Acceleration increases the load or demands on multiple components, including tyres, axles, driveshafts, transmission, or engine.
If one of these elements is worn out, misaligned, or defective, it will adversely affect the transfer of power to the wheels and create uneven forces, which causes shaking in the vehicle.
For example, unbalanced tyres can cause the vehicle to wobble or shake at high speeds; defective CV joints will cause the vehicle to shake in a repetitive motion pattern that increases as the vehicle accelerates. Engine or transmission mounts are designed to absorb some of the vibrations from the powertrain.
When these mounts are damaged, they allow excess movement. Knowing some or all of these particular components can help you identify the source of the shaking in the vehicle early.
Main causes of car shaking when accelerating
Even minor vibrations can signal a deeper mechanical issue. Below are the common reasons behind a car shaking under acceleration, along with methods to identify them.
Torn or worn engine mounts
Engine mounts connect the engine to the vehicle frame and absorb vibrations. Over time, the rubber part of the mounts can become cracked, weakened, or disbonded due to heat and stress from being tightly fastened in the engine compartment.
If the mounts are damaged, the engine can move significantly under acceleration, causing abrupt shaking or jerking motions, particularly when the vehicle changes gears or accelerates from a stop.
Unbalanced or damaged tyres
Tyres are a key source of vibration if they become unbalanced, worn, or damaged. Conditions such as tread separation, uneven inflation, or bent wheels can cause shaking that worsens as your driving speed increases.
Unbalanced wheels will create oscillation in the steering wheel; uneven wear of tyres creates vibrations that will still be felt even on smooth roads.
Failed CV joints or axles
The CV joints on front or all-wheel-drive vehicles transfer torque from the transmissions to the wheels while allowing some flexibility.
When CV joints wear out, or when the protective rubber boots tear, grease leaks out, and friction occurs between metal and metal. You may sometimes hear a rhythmic vibration or clicking sounds when steering while accelerating quickly.
Worn suspension or steering components
The suspension and steering systems in a vehicle stabilise its handling and absorb shocks from the road. They include control arm bushings, ball joints, struts, tie rods, and many other components that can become worn or loose due to age and use, potentially causing vibration while in motion.
Steering vibration often becomes more pronounced when accelerating or turning at higher speeds.
Bad spark plugs or ignition issues
The engine in your car relies on spark plugs to ignite the right amount of fuel and air at the right time during the combustion process. If one or more spark plugs misfire or produce a weak spark, it will cause the engine to lose power temporarily. In fact, this can lead to jerking or vibration during acceleration. Other items, like ignition coils or plug wires, can also cause this same issue. Common symptoms include rough idling, hesitating during acceleration, and consuming more fuel than necessary.
Transmission problems
Issues with the transmission in your vehicle can lead to shaking or shuddering when you accelerate. When the transmission fluid is low or dirty, it can affect the engagement of gears and torque transfer from the engine, resulting in slippage, vibration, or clunky shifts.
Automatic transmissions can also shudder if the torque converter is not functioning correctly. It is essential to regularly inspect your vehicle's fluid levels and condition to ensure optimal performance.
Dirty or clogged fuel or air filters
Fuel and air filters are crucial for your car’s engine to work more efficiently. If they are clogged with dirt or debris, they will restrict airflow or the fuel supply to the engine, resulting in erratic combustion and loss of power.
The engine may begin to vibrate or hesitate when accelerating because it is struggling to find the optimal air-to-fuel ratio. More often than not, this issue is more prevalent in older cars or those driven frequently in dirty conditions.
Brake system issues
While the brakes are not engaged in the acceleration process, warped rotors or sticky callipers can produce residual vibration felt through the steering wheel or chassis. Warped rotors can potentially rub against the pads regardless of whether the brake pedal is pushed or not.
A sticking calliper can create uneven brake effort and dragging resistance, which will almost always be noticeable immediately after acceleration. A complete brake inspection can uncover uneven rotor thickness or binding callipers.
What to do if your car shakes when accelerating
A car that shakes while accelerating is more than just annoying; it’s a warning. Acting quickly can help you avoid a breakdown and stay safe. Here’s what to do first.
Check tyre condition and wheel balance
Start by checking your tyres; see if there’s uneven (or unusual) tread wear, flat spots, or cracks. Finally, be sure they are inflated to the manufacturer's specifications.
If there is vibration only at particular speeds, first get the wheels balanced and aligned. This will result in evenly distributed weight, reduce vibrations, and help the mileage. This labour is low-cost and will solve most, if not all, shake issues when driving down the highway.
Check the engine mounts
If you experience vibration when accelerating from a stop or during gear shifts, inspect your car’s engine mounts and CV joints. Check the rubber mounts for cracks and the rubber CV boots for leaks.
A mechanic should be able to do this visually and use a physical vibration test while revving the engine in neutral. Replacing the same worn mounts or joints should restore structural stability and smoothness for power transfer.
Replace worn spark plugs
If your car idles roughly or loses power during acceleration, it could indicate a problem with the spark plugs or ignition system. Check the service records, spark plugs should typically be replaced every 30,000–50,000 km.
Also, inspect ignition wires and coils for damage or corrosion. Using spark plugs that meet the manufacturer’s specifications ensures proper combustion timing and can eliminate vibrations caused by misfiring cylinders.
Ensure filters are clean
The performance of the engine is affected when the fuel or air filters are clogged, as the engine struggles to maintain a steady flow of fuel, resulting in vibration.
You should periodically clean or replace these filters according to your driving conditions. Replacing the filters can restore proper airflow, reduce the load on the fuel pump, and return smooth performance when accelerating.
Check transmission and engine fluids
The proper operation of the engine and transmission relies heavily on having clean, sufficient engine and transmission fluids. Low or stale oil adds friction that can be felt as vibration when inputting the throttle. Also, check fluid levels monthly and have the fluids changed at recommended intervals.
Visit a trusted mechanic
You should not ignore a persistent vibration. Mechanics will use diagnostic tools, vibration analysis, and test driving to help assess the source of the vibration. They can help determine if the issue is with the powertrain, tyres, suspension, or problems related to the transmission.
How to prevent car vibration issues
Avoiding the shaking of a car starts with preventative maintenance and attention to small changes in performance. Here’s what you can do to keep your vehicle running without vibration.
Schedule regular maintenance and inspections
Always follow the service schedule provided by your car manufacturer to keep critical components, such as the suspension, transmission, and brake system, in peak condition. You should schedule an inspection every six months to catch early signs of wear and tear.
Our team at ACKO Drive service centres makes regular maintenance easy. Book through the ACKO app or the ACKO Drive website, and we’ll handle everything, from doorstep pickup to a 50+ point inspection with original parts. We thoroughly check the suspension, brakes, engine, tyres, and more to keep your car safe, smooth, and reliable.
Balance and rotate tyres on time
One common cause of vibration is uneven wear on the tyres. Ensure the tyres are balanced each time they are rotated, which should occur every 10,000-12,000 km.
Check for proper wheel alignment after hitting a significant pothole (or any other unknown cause) and whenever high-speed vibration occurs. Balanced tyres reduce rolling resistance and promote even tread wear.
Use quality fuel and engine oil
Filling your car with low-grade fuel or low-quality engine oil can cause incomplete combustion and increased engine friction, resulting in the car shaking, especially during heavy acceleration.
Always fill your fuel tank from reputable suppliers and use engine oil that meets the specifications of your vehicle. A top-quality engine oil provides better protection for moving engine parts, reduces vibrations in the car, and improves the engine's responsiveness.
Change your filters
Replacing your filters, spark plugs, and other wear items in a timely fashion will allow your engine to run at an optimum capacity.
If you wait to replace filters and spark plugs, deposits will build up, restricting airflow and fuel delivery. A properly tuned ignition and intake system will decrease shaking and provide optimal fuel mileage and reliability.
Address small vibrations early
Even a small vibration could be the first sign of a minor issue starting to worsen. A small vibration can quickly escalate into a very costly repair, such as an axle snapping off or a transmission failure.
Watch for any unfamiliar pulsing, shaking of the steering wheel, or a noise related to the driveline. If you address these situations promptly, you may potentially avoid unsafe circumstances and save money in the long term.
Bottom line
A car that shakes during acceleration may seem like a minor issue, but it often signals a mechanical problem that needs attention. Causes can range from uneven tyres and worn engine or transmission mounts to issues with the ignition system or suspension. Early diagnosis and repair can reduce vibrations, extend the life of your vehicle, and improve driving comfort.
Regular inspections and maintenance help prevent these problems. Always prioritise routine vehicle checks, keep your tyres balanced, use quality parts and fluids, and consult a professional if you’re unsure about a diagnosis or repair. Smooth acceleration not only improves driving comfort but also indicates a healthy engine and drivetrain.
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