Check Engine Light Flashing and Car Shaking

If you notice check engine light flashing and car shaking, then there is likely to be an issue with the engine or other part of the car’s drive train.

It does not matter whether you were just in traffic idling or driving somewhere; there has to be a problem.

So, what causes check engine flashing and car shaking?

Generally, if your car is shaking and checking engine flashing, there is an issue with the engine or simply an issue with fuel supply, fault in the ignition coil, bad engine sensor, or poor spark plugs.

If your car shakes when idling, the issue is probably caused by an idle air control valve.

It’s not recommended to drive a car when the check engine flashlight is on or badly shaking.

In this guide, I will be highlighting the possible causes of check engine light and the possible remedies.

What is Check Engine Light?

Check engine light, also known as the malfunction indicator lamp, is a visual signal that warns the driver of a possible fault with the engine or car drivetrain.

Check light engine can be yellow, amber, or orange; it depends on the manufacturer.

It might be a minor issue or an indication of a serious issue like engine misfire resulting in overheating the catalytic converter.

Mostly, it implies that you are about to visit the car dealer soon.

When the check engine flashes and remains solid, it indicates a malfunction that requires repair as soon as possible since it can lead to damage if not repaired quickly.

Some causes for check engine flashing include insufficient oxygen, faulty fuel issues, leaks in vacuum, broken wires, and worn-out components. If you notice, check the engine light on, take it to a professional for repair.

Check Engine Light Flashing and Car Shaking Causes and Fixes

Here are the causes and fixes for each cause

1. Blocked Fuel Filter

When you push on the accelerator, it can cause an engine misfire, which causes car shaking.

It mostly happens when there is insufficient fuel pressure in the cylinder; when the fuel injector does not get enough fuel, the cylinder will misfire because of the wrong air to fuel ratio.

Fuel filters are serviceable; thus, ensure your diesel car every two years or 30,000 miles and if your car is a petrol one, change after four years or 50,000 miles.

Fuel and dirt from contaminated water or fuel can damage the fuel filter or block it.

Therefore, your car will trigger a check engine light due to a bad poor fuel filter resulting from the blockage.

Fixing: If the error code directs to an issue with fuel pressure, check for any leakages and blockages and then change the fuel filter.

2. Faulty Ignition Coil

Ignition coils are small transformers that give a high voltage current to power the spark plug. Thus, if there is a fault in the ignition coil, it leads to engine shaking and misfires.

The signs of faulty ignition are decreased power, engine misfires, rough engine idle, bad oil economy, and a difficult engine to start.

A faulty ignition coil lacks noise and may not look damaged. However, when you try running the engine, it will have difficulty running properly and will cause check engine light and probably engine trouble codes.

If there is a bad ignition coil, when you conduct a diagnostic test, it is likely to show error code P0351 to P0358.

Fixing: Check whether all the ignition coils are working perfectly and change the spark plugs.

3. Bad Fuel Injector

A bad fuel injector is a popular cause of check light engine and shaking engine. Modern engines use direct injections to fuel the engine. By using ECU, fuel injectors deliver an exact amount of fuel into the engine.

Fuel injectors fail if they start leaking or the nozzle gets blocked by dirt.

So, after shutting your engine off, the fuel injectors may remain hot longer due to heat emitted by the engine.

Therefore, any remains of fuel in the injector evaporate and leave hard hydrocarbon deposits in the tip of the fuel injector.

The deposits build up with time hence blocking the injector.

Fixing: when you encounter error codes P0301 to P0304, it indicates an issue with fuel ignition in the cylinder.

To fix this, change the spark plugs and check to confirm all the ignition coils are working.

4. Bad Spark Plugs

If one of the spark plugs is faulty, it may lead to a misfire of the affected cylinder.

When there are continuous misfires, it causes rough and shaking engine which results to check engine light. Bad spark errors will likely be P0300, P0430, and P0420.

Spark plugs are meant to work under extreme conditions and give a high-quality spark at specific intervals.

With time, spark plugs may fail to operate due to dirt or being worn out.

Also, spark plugs may fail due to building up carbon deposits on their tip due to the ratio imbalance of old fuel to air. They can also burn, corrode, or get contaminated by the engine oil.

Fixing: Check the spark plug which does not function properly and change them.

5. Bad Engine Sensor

Sensors monitor every engine function and condition like the amount of air entering the engine, the temperature of the engine, air and fuel pressure, timing of the engine, the composition of exhaust gas, and engine oil pressure.

Thus, a bad engine sensor can adversely affect the engine’s performance and cause shaking, poor fuel economy, and lack of engine power.

Fixing: Change the bad sensor and clear the trouble code from the memory of the ECU.

6. Bad Idle Air Control Valve

It means that the car shakes when sitting but stops when driving.

A faulty idle air control valve leads to car shaking because there is no air getting into the cylinders.

Thus, a faulty idle air control valve impacts the air entering your car’s engine when idling, causing it to misfire hence the shaking.

Bad idle air control valve also causes error code P0505 and check engine light.

The good news is that if the check engine light is blinking, then there is almost certainly an engine trouble code stored in the ECU. So the first step in diagnosing the problem is to run a diagnostic using an error code reader.

Fixing: Perform various tests on the IAC to assess if it responds well to changing engine conditions. It will help to point you in the direction of the problem.

 Can I Drive My Car With The Check Engine Light Blinking?

No, it is not advisable to drive your vehicle when the check engine light is blinking.

A check engine light is meant to warn you if something is not right.

Therefore, if the check engine light is flashing, it indicates there is an issue, and thus you should not drive lest you face damage to the engine.

It is a signal of engine misfire and can be caused by engine overheating.

However, if the check engine light is static, it signals a minor engine sensor failure. You can thus drive the car but ensure you get it checked out.

Final Thoughts on Check Engine Light and Car Shaking

When the check engine light flashes, it could get you panicking because probably you don’t understand whether it’s a major issue or not.

However, do not drive a car when the check engine flashlight is on or badly shaking because it can cause serious damages and cost you even more.

Therefore, keep in mind that, check the engine light indicates an emergency, and you should ensure a mechanic checks your car.


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