Car Shaking While Idle Check Engine Light

Causes of Car Shaking While Idle

1. Engine Misfire

A misfire occurs when the combustion process in one or more cylinders is disrupted. This can be caused by a variety of factors, including faulty spark plugs, ignition coils, or fuel injectors. A misfire can cause the engine to shake violently, especially at idle.

2. Vacuum Leak

A vacuum leak occurs when air leaks into the engine through a hole or crack in the intake system. This can cause the engine to run lean, which can lead to shaking and other performance issues.

3. Faulty EGR Valve

The EGR (exhaust gas recirculation) valve recirculates exhaust gases back into the engine. This helps to reduce emissions and improve fuel economy. A faulty EGR valve can cause the engine to shake at idle.

4. Dirty Throttle Body

The throttle body controls the amount of air that enters the engine. A dirty throttle body can restrict airflow, which can cause the engine to shake at idle.

5. Worn Motor Mounts

Motor mounts are designed to absorb vibrations from the engine. Worn motor mounts can allow the engine to shake excessively, especially at idle.

Symptoms of a Check Engine Light

1. Illuminated Check Engine Light

The most obvious symptom of a check engine light is, of course, the illuminated light itself. The check engine light is designed to alert you to a problem with the engine or emissions system.

2. Rough Idle

A rough idle is another common symptom of a check engine light. This can be caused by a variety of factors, including misfires, vacuum leaks, and faulty EGR valves.

3. Decreased Performance

If your car is experiencing decreased performance, it could be a sign of a check engine light problem. This can be caused by misfires, vacuum leaks, and other issues that can affect engine performance.

4. Increased Emissions

A check engine light problem can also lead to increased emissions. This can be caused by faulty emissions control devices, such as the catalytic converter or oxygen sensors.

What to Do If Your Car Is Shaking While Idle and the Check Engine Light Is On

1. Check the engine oil level. Low engine oil can cause the engine to shake and damage the internal components.
2. Inspect the air filter. A dirty air filter can restrict airflow and cause the engine to shake.
3. Scan the engine for codes. This will help you identify the underlying cause of the shaking and check engine light.
4. Have the engine diagnosed and repaired by a qualified mechanic. Attempting to fix the problem yourself could void your warranty and cause further damage to the engine.

Conclusion

If your car is shaking while idle and the check engine light is on, it is important to have the problem diagnosed and repaired as soon as possible. Ignoring the problem can lead to further damage to the engine and other components. A qualified mechanic can help you determine the cause of the problem and recommend the best course of action.