Why is my car shaking and the engine light blinking?

A blinking engine light with noticeable shaking usually points to a serious engine issue, most commonly an engine misfire. Stop driving as safely as possible and arrange a diagnostic shortly to prevent further damage.

In detail, this combination signals that the engine management system has detected a fault affecting ignition, fuel delivery, or emissions controls. Causes can range from a simple sensor hiccup to a misfiring cylinder or a mechanical fault. Prompt diagnosis is essential to protect the engine, avoid costly repairs, and stay safe on the road.

What the blinking light typically signals

The flashing check engine light is an urgent warning. When it flickers while you’re driving, it usually points to a misfire or another critical fault that could damage the catalytic converter if driven at speed or under heavy load.

Common culprits behind a shaking engine and a blinking light include problems with ignition, fuel delivery, and air management. Below are the most frequent causes to consider.



• Engine misfire caused by faulty spark plugs, worn spark plug wires, or defective ignition coils


• Ignition system problems such as a failing coil pack or compromised spark wires


• Inadequate or irregular fuel delivery from a weak fuel pump, clogged fuel filter, or dirty/clogged fuel injectors


• Vacuum leaks or cracked intake hoses that skew the air-fuel mixture


• Faulty sensors such as a Mass Air Flow (MAF) sensor or Oxygen (O2) sensors leading to incorrect fuel trimming


• Dirty or malfunctioning throttle body or idle air control components affecting idle quality


• Exhaust system problems or a failing catalytic converter that reduces engine efficiency


• Timing issues from a worn timing belt/chain or tensioner in rare cases, which can cause misfire and shaking

When the list above aligns with your symptoms, a professional diagnostic is warranted. Driving with a blinking light can allow unburned fuel to reach the catalytic converter, potentially causing costly damage.

What to do right now

To reduce risk and gather information for a mechanic, follow these safety and diagnostic steps.

Use this checklist to stay safe and collect helpful details before a repair shop visit.



• Safely pull over and switch off the engine as soon as you can do so without creating a hazard; if you’re in traffic, reduce speed gradually and find a safe place to stop


• Avoid driving long distances or on highways while the light is blinking; arrange roadside assistance if needed


• Check for obvious issues such as a loose gas cap or visible fluid leaks; tighten the gas cap if loose


• Note any unusual smells (fuel, burning oil) or noises (ticking, banging) and when the shaking occurs (idle, acceleration, or cruise)


• If possible, read the diagnostic trouble codes (DTCs) using an OBD-II scanner or have a shop read them for you; many auto parts stores offer free scans


• Document the symptoms and codes to share with the technician to speed up diagnosis

These steps protect you and help guide the repair process. A professional diagnosis is the quickest path to a safe, lasting fix.

How professionals diagnose and fix

Mechanics follow a structured workflow to identify the fault and ensure proper repair, safety, and emissions compliance.

1. Retrieve diagnostic trouble codes (DTCs) with an OBD-II scanner and review live data for misfire indicators and sensor readings


2. Inspect ignition components (spark plugs, ignition coils, wiring) for wear or failure and replace as needed


3. Test the fuel system, including fuel pressure, pump operation, and injector performance; clean or replace injectors if necessary


4. Check for vacuum leaks, cracked hoses, and PCV or EGR system faults that could upset the air-fuel mix


5. Assess sensor health (MAF, MAF/MAP sensors, O2 sensors) and correct any erroneous readings with replacements or recalibration


6. If the issue persists, perform engine compression or leak-down tests to check for internal mechanical problems


7. Inspect the exhaust system and catalytic converter performance; diagnose potential converter damage or restricted exhaust flow


8. Carry out required repairs, clear codes, and perform a road test followed by a re-scan to confirm the fault is resolved

Costs vary by diagnosis and repair, but addressing a misfire or critical fault promptly helps prevent catalytic converter damage and higher repair bills.

Summary

A car that shakes with a blinking engine light is a red flag that usually points to a misfire or another serious engine fault. Immediate safety steps include pulling over safely and seeking a professional diagnostic. Common causes range from ignition and fuel delivery issues to vacuum leaks and sensor faults. With a proper inspection and timely repair, you can restore performance, protect the exhaust system, and avoid roadside breakdowns.

Why is my check engine light blinking and shaking?

One of the most common reasons for a flashing check engine light paired with a shaking car is an engine misfire. Misfires occur when one or more cylinders in the engine fail to ignite the air-fuel mixture properly. This disrupts the engine's performance and can cause noticeable vibrations.

Is it safe to drive my car if the engine is shaking?

It is not safe to drive with a shaking engine, especially if the check engine light is flashing, as this can cause serious and costly damage to other components. The shaking is a symptom of a serious issue like a severe engine misfire, a bad motor mount, or transmission problems, and you should get it diagnosed by a mechanic immediately. 
Risks of driving a shaking car

• Severe engine damage: A severe misfire can lead to catastrophic damage to the catalytic converter and other expensive engine components. 
• Loss of control: The shaking can be a sign of issues with suspension or alignment, which can compromise your steering and put you at risk of an accident. 
• Increased costs: Continuing to drive can turn a potentially minor repair into a major one. 

This video explains the causes and solutions for a shaking car engine: 59sHelpful DIYYouTube · Feb 8, 2023
What to do

1. Pull over and turn off the engine: as soon as it is safe to do so. 
2. Call for a tow truck: to take your car to a mechanic for a professional diagnosis and repair. 
3. Avoid driving: until the problem is fixed. 

Common causes of engine shaking

• Severe misfire: One or more cylinders are not firing correctly, often due to problems with spark plugs, ignition coils, or fuel injectors. 
• Damaged engine or transmission mounts: These hold the engine in place. If they are broken or worn, the engine will move excessively and cause vibrations. 
• Transmission issues: Problems with the transmission can cause shaking when shifting gears. 
• Other problems: Worn CV joints, driveshaft issues, or even unbalanced tires or suspension problems can also cause vibrations. 

Can I still drive my car if the engine light is flashing?

No, you should not drive with a flashing check engine light. A flashing light indicates a serious problem, such as a severe engine misfire, that could cause immediate and costly damage if you continue to drive. Pull over safely as soon as possible and have the vehicle towed to a mechanic for diagnosis.
 
This video explains what to do if your check engine light is flashing: 55sFaye HadleyYouTube · Jan 29, 2022
What to do immediately

• Pull over safely: Find a safe place to stop the car as soon as you can. 
• Do not drive: Avoid driving any further than necessary to get to a safe location. 
• Call for a tow: Have the vehicle towed to a mechanic or repair shop to prevent further damage. 

What a flashing light means

• Serious problem: The flashing light indicates a severe, active problem, unlike a solid light which can often be addressed with a bit more time. 
• Engine misfire: The most common cause is a misfire, where a cylinder is not firing correctly. 
• Risk of damage: Continuing to drive can lead to major damage, especially to the catalytic converter, turning a smaller repair into a very expensive one. 
• Other components: Other causes can include a leaking fuel injector, faulty oxygen sensor, or even internal engine issues like a broken timing belt. 

This video explains why a flashing check engine light is dangerous: 1mproclaimliberty2000YouTube · Dec 13, 2019

Can low oil cause engine shaking?

Yes, low engine oil can cause a car to shake, especially when idling, because it leads to increased friction between engine parts that are not being properly lubricated. This friction can cause vibrations and, if left unaddressed, can lead to more severe engine damage. 
How low oil causes shaking

• Insufficient lubrication: Engine oil lubricates moving parts like the pistons, bearings, and cylinders. When the oil level is low, these parts don't have enough oil to reduce friction and operate smoothly. 
• Increased friction: The lack of proper lubrication causes parts to rub against each other, which generates heat and creates excess vibration. 
• Engine damage: In severe cases, the excessive friction from low oil can cause components to expand and seize, leading to knocking or serious internal engine damage over time. 

What to do if your car is shaking

• Check the oil level: Immediately check your oil dipstick to see the current oil level. 
• Add oil if low: If the oil is low, add the correct grade of oil to bring it back to the recommended level. 
• Monitor the shaking: See if the shaking stops after you add oil. If it persists, there may be other issues or existing damage. 
• Visit a mechanic: If the shaking continues, it's best to have a mechanic diagnose the problem to rule out other issues and check for any existing damage from running with low oil.