Experiencing a car that shakes and struggles to accelerate can be a frustrating and concerning issue for any driver.
The sensation of your car vibrating or trembling while attempting to pick up speed is not only unsettling but also potentially dangerous.
We outline the reasons why your car shakes and fails to accelerate as well as how to address the problem.
Reasons for car shaking and not accelerating
Here’s why a car shakes and struggles to accelerate:
1. Engine misfire
An engine misfire occurs when one or more cylinders fail to ignite the air-fuel mixture properly within the combustion chamber.
This disruption in the combustion process can result in a range of issues, including shaking, vibration, and difficulty accelerating.
This is how an engine misfire leads to a car shaking and not accelerating:
Uneven power delivery: When a cylinder misfires, the engine’s power output becomes irregular.
As a result, the car might shake or exhibit a noticeable lack of power when attempting to accelerate, especially during higher demands on the engine, such as when merging onto highways or climbing hills.
Vibration and shaking: A misfiring cylinder can cause the engine to run unevenly, leading to noticeable vibrations and shaking felt throughout the vehicle, particularly during acceleration or at specific RPM ranges.
Hesitation or jerking sensation: During acceleration, an engine misfire might cause the car to hesitate or jerk intermittently, as the engine struggles to maintain a consistent and smooth power delivery.
Signs of engine misfire:
- A flashing or steady check engine light on the dashboard often indicates an engine misfire.
- Rough idling with noticeable vibrations felt through the steering wheel or throughout the car.
- Reduced engine power, poor acceleration, and difficulty maintaining speed, especially under load, are common signs of an engine misfire.
- A misfiring engine can produce irregular exhaust emissions, potentially accompanied by a noticeable smell of unburned fuel in the exhaust.
- In severe cases, an engine misfire might lead to engine stalling, particularly when the car is idling or when accelerating abruptly.
Solution:
Diagnosing and addressing engine misfires typically involves inspecting components like spark plugs, ignition coils, spark plug wires (if equipped), and the engine control unit (ECU).
Seek the expertise of a qualified mechanic to diagnose and resolve this problem.
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2. Fuel system issues
A car that is shaking and not accelerating can be due to fuel system issues.
Fuel system issues can significantly impact a car’s performance, leading to shaking and poor acceleration due to inadequate fuel reaching the engine.
This is how fuel system issues affect performance:
Clogged Fuel Filter: A clogged fuel filter impedes the flow of fuel from the tank to the engine. When the filter becomes dirty or blocked, it restricts the amount of fuel reaching the engine.
As a result, the engine might struggle to get the necessary fuel supply during acceleration, causing the car to shake or hesitate.
Dirty Fuel Injectors: Fuel injectors spray fuel into the combustion chamber in a precise manner. Over time, these injectors can become clogged or dirty, disrupting the fuel spray pattern and leading to an uneven air-fuel mixture.
This inconsistency in the fuel delivery can cause engine misfires, resulting in shaking or jerking sensations when accelerating.
Malfunctioning Fuel Pump: The fuel pump is responsible for pumping fuel from the tank to the engine. If it’s failing or not delivering fuel at the correct pressure, the engine may not receive enough fuel for proper combustion.
This deficiency can cause the car to sputter, shake, or hesitate when accelerating, as the engine struggles to function optimally.
Signs of fuel system issues:
- Rough idling.
- Decreased fuel efficiency.
- Engine stalling
- Check engine light on the dashboard.
- Hesitation or jerking when accelerating.
- Lack of engine power.
Solution:
Addressing fuel system issues promptly is important to avoid further damage to the engine.
Seek the expertise of a qualified mechanic to diagnose and resolve fuel system-related problems.
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3. Transmission problems
A car that is shaking and not accelerating can also be due to transmission problems.
Transmission problems can significantly impact a vehicle’s ability to accelerate smoothly and cause shaking or trembling sensations.
Here’s how transmission problems affect performance:
Low transmission fluid: Adequate transmission fluid is crucial for proper lubrication and hydraulic functions within the transmission.
Low fluid levels or degraded fluid quality can lead to issues such as slipping gears, which result in a lack of power transfer from the engine to the wheels.
This slippage can cause the car to shake or hesitate during acceleration as the transmission struggles to engage properly.
Worn clutch (manual transmission): In manual transmissions, a worn-out or slipping clutch can prevent the engine’s power from efficiently reaching the transmission and subsequently the wheels.
This issue can cause the car to shake or exhibit poor acceleration, particularly when performance gears.
Malfunctioning torque converter (automatic transmission): An issue with the torque converter, a key component in automatic transmissions, can result in a lack of power transfer between the engine and transmission.
This leads to a noticeable delay or hesitation in acceleration, accompanied by shaking or vibration as the transmission struggles to engage properly.
Signs of transmission problems:
- Delayed or rough performance: Difficulty or delays in performance gears, including harsh or abrupt gear changes. This symptom might be accompanied by jolting or shaking sensations during gear shifts.
- Slipping gears: A slipping sensation where the engine revs increase without a corresponding increase in car speed can suggest slipping gears within the transmission, leading to a lack of acceleration and shaking.
- Burning smell or fluid leaks: A burning smell or visible leaks beneath the car could indicate overheating or leaking transmission fluid, signaling potential transmission problems.
- Unusual noises: Grinding, whining, or clunking noises while changing gears or during acceleration can be indicative of transmission issues, such as worn-out gears or damaged components.
- Dashboard warning lights: The illumination of the transmission or check engine light on the dashboard.
Solution:
Have a qualified mechanic conduct a thorough inspection and diagnosis.
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4. Wheel and tire issues
A car that is shaking and not accelerating can also be due to wheel and tire issues.
Problems with wheels and tires can affect a car’s behavior including causing noticeable vibrations, shaking, and difficulties with acceleration.
This is how wheel and tire issues affect performance:
Imbalanced or misaligned wheels:
Uneven distribution of weight around the wheel or tire can cause imbalances. When the wheels are imbalanced, the car may vibrate, particularly at higher speeds.
This vibration can be felt through the steering wheel and throughout the vehicle, affecting acceleration and causing a lack of smoothness.
Improper alignment of wheels can also lead to uneven tire wear and affect how the car handles.
Misaligned wheels can cause the car to pull to one side, contribute to steering wheel vibration, and lead to difficulties in maintaining speed or accelerating smoothly.
Worn-out tires or suspension issues:
Tires with uneven tread wear, bald spots, or low tread depth can create vibrations and affect the vehicle’s stability. This can result in shaking or vibrations felt during acceleration.
On the other hand, issues with the suspension components, such as worn-out shocks, struts, or damaged suspension parts, can lead to instability and vibrations while driving.
These problems can impact acceleration and cause a bumpy or shaky ride.
Signs of wheel and tire issues:
- Vibrations felt through the steering wheel, floorboard, or seats, especially at certain speeds.
- Shaking or wobbling of the steering wheel, particularly during acceleration, braking, or at specific speeds.
- Pulling or drifting of your car, that is, your pulls to one side while driving or the steering feels off-center, it could be a sign of misaligned wheels, uneven tire pressure, or suspension problems.
- Uneven tire wear indicated by uneven tread wear patterns on tires, bald spots, or visible damage.
- Difficulty accelerating or maintaining speed.
Solution:
Seek the assistance of a professional mechanic to assess the condition of the tires, wheels, and suspension components to identify and address any underlying issues.
Regular maintenance, including wheel balancing, tire rotation, proper tire inflation, and wheel alignments, helps to prevent many wheel and tire-related problems.
5. Air intake or exhaust problems
Issues within the air intake or exhaust systems can significantly affect a vehicle’s performance, leading to shaking and difficulties with acceleration.
This is how air intake or exhaust problems affect performance:
Air Intake Issues: Blockages in the air intake system, such as a clogged air filter or a blocked intake manifold, can limit the amount of air entering the engine.
Reduced airflow can disturb the air-fuel ratio, causing an improper combustion mixture and resulting in a lack of power during acceleration.
Leaks in the intake system can allow unmetered air to enter the engine, affecting the air-fuel mixture. This can lead to irregular engine operation, rough idling, and hesitation during acceleration.
Exhaust system problems: Blockages or restrictions in the exhaust system, such as a clogged catalytic converter or a damaged muffler, can impede the flow of exhaust gases.
This obstruction can lead to increased back pressure in the engine, causing a reduction in power output and potentially causing the car to shake or hesitate during acceleration.
Leaks in the exhaust system, such as cracked or damaged exhaust pipes or gaskets, can lead to the escape of exhaust gasses before they properly exit the system.
This can disrupt engine performance and cause vibrations or shaking, especially during acceleration.
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Signs of air intake or exhaust problems:
- Reduced power and acceleration.
- Rough idling.
- Hissing sounds (indicating vacuum leaks), rattling, or loud exhaust noises can be signs of problems within the air intake or exhaust systems.
- Excessive exhaust smoke
- Check engine light illumination on the dashboard.
Solution:
A qualified mechanic needs to inspect and address air intake or exhaust system issues. This involves checking for blockages, leaks, or damage in the intake and exhaust components.
Repairing or replacing damaged parts and ensuring proper airflow and exhaust flow are crucial steps to restore the vehicle’s performance and prevent further damage to the engine or emissions systems.