Is it Safe to Drive With My Car Engine Shaking?

Four common symptoms for the engine shaking while driving can develop into loss of power, increased damage, potential breakdown and fire hazard

No, it is generally not safe to drive with your car engine shaking. While a slight vibration at certain speeds might be normal due to engine rotation, excessive shaking is a warning sign that something is wrong and could lead to further damage or even an accident.

Here's why driving with a shaking engine is risky:

Loss of power: The increased friction, bad combustion, and potential component damage can all decrease overall engine efficiency. This means the engine needs to work harder to produce the same amount of power, leading to power loss.
Increased damage: Ignoring the shaking can worsen the underlying problem, leading to expensive repairs later.
Potential breakdown: The shaking could be a symptom of a major issue that could cause your car to break down while you're driving, leaving you stranded.
Fire hazard: In some cases, severe engine shaking caused by internal issues like worn piston rings or excessive heat can lead to leaks or spills of flammable fluids like oil or coolant. Continued driving with these leaks increases the risk of a fire starting under the hood, potentially spreading and engulfing the entire vehicle.

Why is my engine shaking when I accelerate?

Here are some of the most common culprits:

Engine and Drivetrain Issues

Misfiring engine: If one or more cylinders aren't firing properly, it can make the engine misfire, causing vibrations. This can be due to worn spark plugs, faulty ignition coils, or other issues.
Faulty engine mounts: These rubber mounts absorb engine vibrations, but if they're damaged or worn out, the shaking will be transmitted to the car. Plus, broken motor mounts can quickly develop into more extensive issues.

Faulty engine mounts causing the vehicle and engine to vibrate while driving

CV joint problems: Constant velocity joints transfer power from the engine to the wheels. If they're worn or damaged, it can cause shaking, especially when turning or accelerating.
Driveshaft issues: A bent or damaged driveshaft can also cause shaking, particularly at higher speeds.

Faulty driveshaft carrier bearing causing the vehicle to shake when accelerating

Tire and Wheel Issues

Unbalanced tires: This is the most frequent cause of shaking during acceleration; this one heavily affects the steering wheel. When tires are imbalanced, they create an uneven weight distribution that causes the entire car to vibrate.

Unbalanced tires with deformities, causing the steering wheel to shake and vibrate while driving

Misaligned wheels: Similar to unbalanced tires, misaligned wheels result in car shakes due to uneven contact with the road. This issue also results in the steering wheel shaking.
Loose lug nuts: If the lug nuts aren't tightened properly, the wheel bearings won't be safely tight. So, the wheels can wobble and cause shaking.

Loose lug nuts causing the vehicle to shake when driving and accelerating

Other Potential Causes

Stuck brake caliper: If your brake pedal also vibrates, then the problem might be in the brake system. If a brake caliper is stuck, it can cause the brakes to drag and create a vibration.

Stuck brake caliper causing the brake to partially apply, generating heat and vibrations on the steering wheel

Transmission problems: In rare cases, internal transmission issues can cause shaking during acceleration.

Why is my engine shaking at idle?

Here are some of the most common culprits:

Ignition System Issues

Worn spark plugs: Worn spark plugs can cause incomplete combustion, leading to rough idling and shaking.

Worn spark plugs comparison between a worn out with a new one

Faulty ignition coils: If the ignition coils fail to deliver sufficient voltage, it can result in misfires and engine shaking.

Ignition coil is faulty and triggering the check engine light on the dashboard while also causing engine sputtering and vibrations

Dirty or damaged spark plug wires: These wires carry the electrical signal to the spark plugs. If they're dirty or damaged, the spark can be weak or inconsistent, causing shaking.

Fuel System Issues

Dirty fuel injectors: Clogged injectors can prevent the engine from getting the proper amount of fuel, leading to uneven combustion and shaking.

Dirty fuel injectors cause the engine to receive unproper fuel amounts, leading to bad combustion and vibrations while also making the car struggle to start

Vacuum leaks: A vacuum leak allows unmetered air into the engine, disrupting the air-fuel mixture and causing rough idling.
Dirty air filter: A clogged air filter restricts airflow, affecting the air-fuel mixture and potentially causing shaking.

Poor air filter causing the engine to have a bad airflow, resulting in overheating, vibrations, and warnings

Engine Mechanical Issues

Internal engine problems: In rare cases, worn piston rings, valve issues, or other internal problems can cause engine imbalance and shaking.

Other Potential Causes

Loose belts or pulleys: Worn or loose belts and pulleys can create vibrations that translate to the engine.
Faulty idle air control valve: This valve regulates the engine's idle speed. If it's malfunctioning, it can cause the engine to run rough and shake.

What to do next

Here's what you can do to prevent further damage and ensure your safety:

Call a Shop nearby (you can find one here): Don't ignore the problem. A qualified mechanic can diagnose the issue using specialized tools and recommend the necessary repairs.
Describe the shaking: Be as specific as possible when describing the shaking to the mechanic. Mention the severity, when it occurs (constantly, only when cold, etc.), and any other symptoms you notice.
Consider recent maintenance: If you've had any recent repairs or maintenance, share that information with the mechanic as it might be relevant.

Author: Uwe Kleinschmidt