How do you fix a car that shakes when accelerating?
A car that shakes during acceleration is most often caused by tire or wheel issues, drivetrain components, or engine misfires, and the fix depends on the underlying problem. In many cases, tire or wheel repairs can resolve the problem, but other causes may require parts replacement or professional service.
The shaking you feel when you press the gas pedal can stem from several systems working together under load. This guide outlines the primary causes, practical diagnostic steps, and typical fixes to help you decide what to inspect first and when to call a mechanic.
Common causes of shaking during acceleration
Several systems can cause shake under load. The most frequent culprits involve wheels and tires, engine performance, drivetrain components, and transmission behavior. The sections below explain what to look for and how fixes differ by category.
Wheels and tires
Issues with balance, alignment, or tire condition are the most frequent causes of shake under acceleration.
- Unbalanced wheels or out-of-round tires
- Damaged or bent rims
- Worn, cupped, or uneven tire tread
- Under- or over-inflated tires
- Loose or missing lug nuts
Wheels or tire problems are usually the easiest to diagnose and fix, often resolved by balancing, alignment, or replacing tires or rims. If the shake persists after tire service, other causes should be investigated.
Engine misfire or fuel/air delivery problems
Shaking that feels like the engine is “missing” or vibrating under load can indicate ignition or fuel delivery issues.
- Faulty spark plugs or ignition coils
- Dirty or failing fuel injectors
- Vacuum leaks or a dirty air filter
- Low fuel pressure or a failing fuel pump
Addressing misfires often involves replacing worn spark plugs or ignition coils and cleaning or replacing injectors or filters, plus checking for vacuum leaks. If a misfire is severe, avoid driving the car until it’s diagnosed and repaired to prevent damage.
Drivetrain and engine/transmission mounts
Worn mounts or damaged drivetrain components can transmit vibrations that intensify during acceleration.
- Worn or cracked engine or transmission mounts
- Damaged or worn CV joints or drive shafts
- Worn universal joints (U-joints) with play
Replacing mounts or faulty joints typically resolves these vibrations, though the work can be labor-intensive and may require a shop visit.
Torque converter and transmission issues
Automatic transmissions and some manual setups can cause shaking if the torque converter is slipping, the clutch is failing, or the transmission is low on fluid.
- Low or burnt transmission fluid
- Torque converter problems or slipping gears
- Worn or damaged clutch in manual transmission
Transmission-related vibrations usually require professional service, including fluid checks or replacement and potential component repair.
How to diagnose the issue (practical steps)
Start with the simplest checks and use a structured approach to isolate the cause. The following steps help you determine whether the problem is tire-related, engine-related, or a drivetrain issue.
- Check tire pressure and inspect tires for wear, bulges, or sidewall damage.
- Inspect wheels for bending and have them balanced and aligned if needed.
- Listen for misfires: monitor idle quality, check engine light codes, and inspect spark plugs and ignition coils.
- Check for vacuum leaks and inspect the air filter; test or verify fuel pressure if you have the tools.
- Inspect engine and transmission mounts for cracks, breaks, or excessive movement.
- For vehicles with CV joints or driveshafts, check for play, clicking, or vibration at different speeds.
- Check transmission fluid level and condition if you suspect transmission issues.
Note: If you are not comfortable performing these checks, or if the check engine light is on with codes, seek a qualified mechanic. Driving with certain issues can cause further damage or safety risk.
When to consult a professional
While many wheel and tire issues can be addressed at home, more complex problems—especially engine misfires, CV joints, or transmission problems—usually require a professional diagnostic and repair to ensure safety and prevent collateral damage.
What to expect in a repair
Based on the diagnosis, the repair could involve wheel balancing, tire or rim replacement, spark plug/coil replacement, CV axle replacement, engine mount replacement, or transmission service. Costs vary widely by vehicle and location, so get a clear estimate before authorizing work.
Summary
Shaking during acceleration is a common symptom with multiple potential causes. A structured diagnostic approach focused on tires, engine health, and drivetrain mounts helps identify the root cause. Start with simple tire-related fixes, then systematically test engine and drivetrain components, and seek professional help if the problem persists or codes appear. Regular maintenance and timely repair prevent progression of damage and keep the car safe to drive.
Can low oil cause a car to shake when accelerating?
Yes, low engine oil can cause a car to shake, especially when accelerating, because it leads to poor lubrication and increased friction between engine parts. This lack of lubrication can cause knocking, overheating, and severe damage over time.
How low oil causes shaking
- Insufficient lubrication: Engine oil lubricates and cushions moving parts like the crankshaft, pistons, and bearings. When the oil level is too low, these parts experience increased friction.
- Friction and heat: The metal-on-metal friction creates excessive heat and can cause components to wear down prematurely.
- Engine misfires and knocking: Insufficient oil can cause engine knocking, a sharp knocking sound that is often a sign of bearing issues. It can also lead to rough acceleration as the engine struggles to operate smoothly.
- Severe damage: If the shaking is severe and accompanied by loud knocking, it could be a sign of imminent internal engine damage, such as damaged bearings, which can lead to a complete engine failure.
What to do if your car is shaking
- Stop driving immediately: Pull over to a safe location and turn off the engine to prevent further damage.
- Check the oil level: Use the dipstick to check the oil level. If it's low, add the manufacturer-recommended oil.
- Inspect for leaks: Look for any signs of an oil leak under the car.
- Seek professional help: It is highly recommended to have a mechanic inspect the vehicle. They can determine if the shaking is due to low oil, a more serious internal engine problem, or another issue like a bad motor mount or transmission trouble.
Other signs of low oil
- Oil pressure or check engine light illuminated on the dashboard
- Engine knocking or loud noises
- Burning smell from the engine
- Poor acceleration and sluggish performance
Should I drive my car if it's shaking?
No, it is not always safe to drive when your car is shaking, especially if the shaking is violent, unpredictable, or accompanied by other symptoms like unusual noises. While minor, constant vibrations from something like unbalanced tires might not be immediately dangerous, they can cause further damage and should be addressed soon. If the shaking occurs while braking or at high speeds, it could indicate a critical issue with your brakes or suspension, so it's best to pull over and have the vehicle inspected by a professional.
When to stop driving immediately
- Violent or unpredictable shaking: If the car shakes violently or unpredictably, you should stop driving immediately. This could indicate a serious problem like a broken engine mount or a severe steering issue.
- Shaking during braking: This can be a sign of warped brake rotors or other brake problems, which compromise your ability to stop safely.
- Shaking that affects steering: If you have difficulty controlling the vehicle, pull over as soon as it's safe to do so.
- Shaking accompanied by unusual noises: Loud noises or the car jerking when accelerating can signal engine or transmission problems that need professional attention.
When to get it checked soon
- Shaking at a specific speed: A vibration that starts at a certain speed (e.g., 55-65 mph) often points to unbalanced wheels. While not a life-threatening emergency, it should be fixed soon to prevent wear on other parts like the suspension.
- Shaking while idling: This can be caused by loose engine mounts or other engine-related issues. It's not as immediately critical as violent shaking, but still needs to be diagnosed and repaired to prevent further damage.
What to do if your car is shaking
- Pull over safely: If the shaking is severe or happens during braking, find a safe place to pull over immediately.
- Turn off the engine: This can prevent further damage, especially if the shaking is related to the engine.
- Check for visible issues: Look under the hood for anything obviously wrong, but do not attempt complex repairs yourself.
- Contact a professional: Schedule an appointment with a mechanic to have the car inspected. Ignoring the problem can lead to more expensive repairs or unsafe driving conditions.
How do I diagnose car shaking myself?
Why is My Car Shaking While Driving? Vibration is typically originated by a defective or out of balance tire, a worn driveline U-joint or a bent wheel. You may find that the auto shakes in an up and down motion. You may feel the vibration through the steering wheel, seat, or in the brake pedal.
What causes a vehicle to shake when accelerating?
Vibration during acceleration is often caused by issues with wheel balance and tires, which can lead to shaking or shuddering. Other common causes include engine problems like misfires, drivetrain issues such as damaged CV joints or driveshafts, and worn-out motor or transmission mounts. Less common causes include a bent axle or other suspension problems.
Wheel and tire problems
- Improper balance or wear: Uneven tire wear or an imbalance can cause vibrations, especially at certain speeds.
- Loose lug nuts: If lug nuts are not tightened correctly, the wheel can wobble.
- Damaged wheels: Bent rims from potholes or curbs can also cause vibrations.
Engine problems
- Misfiring cylinders: Issues with spark plugs, ignition coils, or fuel injectors can cause the engine to run rough and shake.
- Clogged filters: Dirty air or fuel filters can restrict flow, leading to a hesitation or shake.
Drivetrain and axle issues
- Worn CV joints: The constant velocity (CV) joints connect the transmission to the wheels. Damage can cause vibrations that are more noticeable under acceleration.
- Damaged driveshaft: This can cause vibration, especially in rear- or all-wheel-drive vehicles. Look for dents or signs of leaking universal joints.
Mounts and suspension
- Bad motor or transmission mounts: These hold the engine and transmission in place. When they wear out, the engine's vibrations are no longer dampened, leading to shaking.
- Alignment issues: Improper alignment can lead to uneven tire wear, which in turn causes vibrations.
What to do
- Check tires: Inspect your tires for wear, inflation, and any signs of damage.
- Get an alignment: If your tires are wearing unevenly, have your alignment checked.
- Have a professional check: Because many causes can be serious, it is best to have a mechanic inspect your vehicle for engine, drivetrain, or suspension problems.
