Car Shakes At Idle But Smooths Out While Driving: Everything You Need To Know

Are you facing some problems with your car? Does your car shakes at idle but smooth out while driving? If so, then there are many things you need to do to find the root of the issue.

Mechanical problems in a car are a sensitive matter. First, you need to analyze the engine and then point out the right problem it’s having. Unfortunately, many people make assumptions that turn out to be wrong, making the situation worse.

It would help if you approached these situations logically. Notice every little detail of the problem your car is having. Is it just shaking at idle? Or at low rev as well? Every little detail has to be observed when you try to figure out what is going on. 

Damaged or worn-out parts can affect the performance of your car. In addition, some parts might need a repair or replacement to stop your car from shaking.

Causes Of Car Shakes At Idle But Smooths Out While Driving

Car Shakes At Idle But Smooths Out While Driving: Everything You Need To Know
Alexander Spatari

To figure out the problem, you need to understand some of the underlying causes. Many components can play their part in creating abnormal vibrations in your car.

Engine Mounts

Engine mounts should be the first thing to look at if your car shakes at idle but smooths out while driving. Mounts are the tool that connects your engine motor to the chassis of a vehicle. 

If the motor is shaking, but you don’t feel any drop in the power, then engine mounts could be one of the things you need to check. Even at low rpm, the car might shake due to damaged mounts.

Spark Plugs

Dirty or worn spark plugs are the most common reason that causes the problem to your engine.  Electrodes in spark plugs melt over time which weakens the plugs. 

Spark plugs play an essential role in igniting the fuel. If the plugs don’t work correctly, the engine will start behaving abnormally. However, spark plugs require a change after 3-5 months, so you need to replace them to achieve optimum performance from your motor.

Timing belt

A crack or tear in a timing belt can become a massive problem if you don’t fix it in time. The timing belt works directly with the piston and valves of any engine. The belt also helps the gas distribution process to each cylinder. 

If the belt isn’t replaced and breaks while the motor is running, it will shut down the engine. But, unfortunately, it would also damage the motor’s internal components, and you would need to overhaul the whole motor, which is very costly.

Air Filter

The air filter plays a vital role in providing clean and filtered air to the motor. A smooth flow of air to the motor keeps it cool and controls the combustion of the engine.

A dusty air filter can make changes to the sound of the motor. If the filter is excessively clogged, it will create vibrations to the engine.

Vacuum Tube

As the combustion process takes place, your car needs to smoothly exhaust the fumes and gases the engine creates. If any tube is leaked or clogged with carbon, the motor will shake excessively. It will also have an impact on the performance of your car.

So make sure your car is exhaling all the gases and fumes smoothly. Make sure no tube is leaking. If it is, the gases will enter the cabin of your car and be highly hazardous.

Fuel Pump

Continuous fuel flow to any motor is vital. So any decrease in the flow to the engine will not just affect the performance. It would also make your car shake continuously at idle. The faults in the fuel pump created by dust particles in the fuel also contribute to the shaking.

Throttle Body

The throttle body is the component that provides air to the motor and causes acceleration. Unfortunately, over time dirt starts to form around the parts of the throttle body. If it isn’t serviced regularly due to clogged airflow, your car will shake at idle. 

Fuel Injectors

Due to carbon deposits and other sediments, the injectors start to clog up. If not cleaned in time, the fuel distribution in the pistons will get affected. It may cause extreme vibrations, and your car will shake at idle.

Do get the service of your injectors done in time and make sure no carbon is formed on it. This will help you tackle the problem.

Things Not To Do If Your Car Shakes At Idle But Smooths Out While Driving

Here are the top things you should not do if your car shakes at idle but smooths out while driving:

Don’t Over Speed

If you Overspeed with any of the components mentioned above not working properly, you will create more problems. Then your car will start to shake more but also damage the motor. So overspeeding in this situation won’t work in your favor.


If you think revving at idle will stop the shaking. Well, that’s where you are wrong. Once the rpm comes down after the rev, it creates more vibrations.

Can You Fix This Problem By Yourself?

There are some components which you can replace yourself. Repair them only if you have experience in handling mechanical machinery. However, there are some things which might need a look by an expert.

Make sure you get an inspection done by an expert. They will point out the problem for you, and you can work on it. An expert’s opinion would be precious.

Final Words

If your car shakes at idle but smooths out while driving, all you need is patience. Be patient, and it would be easy for you to find the solution. Otherwise, you will make the situation worse and may end up diagnosing the problem incorrectly.

Once you consider all this information, you will easily find the issue and its solution. We hope this guide has helped you get the answer you need.

You can also read: How Long Does It Take To Charge A Car Battery: An Informative Guide

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