Car Shakes at Idle but Smooths Out While Driving
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When a vehicle vibrates at a standstill, it can surprise the driver. This act may be pointing to an issue with the wheels or tires. Even though, in many cases, the reality is opposed to that.
Usually, a shaking car at idle is a sign of a problem with the engine or transmission. Though, this shaking vanishes when moving because of the increased RPM of the motor.
It is, therefore, essential to take this seriously and get the car checked by a professional mechanic without hesitation. If left unattended, the consequences of the underlying source of the shaking can put your vehicle in danger and cause further harm.
Now, if your car shakes at idle but smooths out while driving, this article is for you as we’ll discuss the possible causes of this issue as well as how to tackle and fix it.
Table of Contents
Why Car Shakes at Idle but Smooths Out While Driving
Car shaking when idle can make the driving experience unpleasant and uncomfortable. There are several reasons for this which include the following:
1. Bad Motor Mounts
Motor mounts secure the engine to the car's frame and absorb vibrations. Over time, motor mounts can wear out or break, leading to excessive engine movement and causing the car to shake at idle.
The shaking may improve or disappear when the vehicle is in motion because the increased speed and airflow can mask the problem.
2. Bad Spark Plugs
Spark plugs ignite the fuel in the engine's cylinders. When spark plugs are worn, dirty, or misfiring, they can cause the engine to run rough at idle, leading to car shaking.
However, when the vehicle is in motion, the engine may run more smoothly, making the shaking less noticeable.
3. Worn Belts
Serpentine, drive, and timing belts keep the engine's components in sync.
When these belts are worn, damaged, or loose, they can cause the engine to run unevenly, leading to shaking at idle.
The shaking may decrease when the car is in motion as the engine components work together more smoothly.
4. Bad Fuel Intake System
The fuel intake system supplies fuel to the engine. When there is a problem with the fuel pump, fuel filter, fuel injectors, or other components, the engine may not receive the proper fuel mixture, leading to shaking at idle.
When the car is in motion, the engine may receive the necessary fuel mixture to run smoothly, reducing the shaking.
5. Damaged Throttle Body
The throttle body controls the airflow to the engine. When it is dirty, clogged, or malfunctioning, it can cause the engine to run rough at idle, leading to shaking.
Once the car is in motion, the increased airflow can help the engine run more smoothly, reducing the shaking.
6. Unbalanced Tires or Wheels
When tires or wheels are unstable, they can cause vibrations throughout the car.
These vibrations may be more noticeable at idle and decrease or disappear when the vehicle is in motion.
How To Diagnose the Problem
Diagnosing the problem can help you determine the underlying cause and find a solution.
Step 1: Check for Dashboard Warning Lights
Any dashboard warning lights could indicate a problem with the car's engine, transmission, or other systems.
Check for any warning lights and take note of any error codes. This information can help a mechanic diagnose the problem more accurately.
Step 2: Check the Motor Mounts
Inspect the motor mounts for wear or damage. If the mounts are worn or broken, it can cause excessive engine movement, leading to shaking. You can visually inspect the mounts or have a mechanic check them.
Step 3: Check the Spark Plugs
Check the spark plugs for signs of wear or damage. If the spark plugs are old, dirty, or misfiring, it can cause the engine to run roughly, leading to shaking. You may need to replace the spark plugs or have a mechanic do it.
Step 4: Check the Belts
Inspect the serpentine, drive, and timing belt for signs of wear or damage. If the belts are loose or damaged, it can cause the engine components to run unevenly, leading to shaking. You may need to tighten or replace the belts.
Step 5: Check the Fuel Intake System
Check the fuel pump, fuel filter, and fuel injectors for signs of wear or damage.
If there is a problem with the fuel intake system, the engine may not receive the proper fuel mixture, leading to shaking. You may need to replace these components or have a mechanic do it.
Step 6: Check the Throttle Body
Inspect the throttle body for dirt, debris, or damage. If the throttle body is dirty, clogged, or malfunctioning, it can cause the engine to run roughly, leading to shaking. You may have to replace the throttle body.
Step 7: Check the Tires and Wheels
Check the tires and wheels for signs of wear or damage. Unbalanced tires or wheels can cause vibrations throughout the car. You may need to have the tires balanced or the wheels aligned.
How To Fix Car Shaking at Idle
You can take the following steps to fix the car shaking at idle.
Step 1: Identify the Underlying Cause
Before you can fix the problem, you need to identify the underlying cause of the shaking.
Check for any dashboard warning lights, and inspect the motor mounts, spark plugs, belts, fuel intake system, throttle body, and tires and wheels for wear or damage.
If you are uncomfortable diagnosing the problem, take your car to a qualified mechanic for a diagnostic test.
Step 2: Replace Faulty Parts
Once you have identified the underlying cause of the shaking, replace any faulty or worn-out parts.
This may include replacing the spark plugs, motor mounts, belts, fuel injectors, or other components. It is best to use high-quality replacement parts to ensure they will last.
Step 3: Clean the Throttle Body
If the throttle body is dirty or clogged, cleaning it can often fix the problem. You can use a throttle body cleaner and a soft-bristled brush to clean the throttle body.
Ensure you follow the manufacturer's instructions not to damage any components.
Step 4: Clean or Replace the Air Filter
A dirty or clogged air filter can cause the engine to run roughly, leading to shaking. Cleaning or replacing the air filter can often fix the problem.
How To Prevent Car Shaking at Idle
The following are helpful tips for preventing car shaking when idle:
1. Regular Maintenance
Regular vehicle maintenance is essential to avoid car shaking at idle. Keep your car's engine, transmission, suspension, and wheels in good working condition by following the manufacturer's recommended maintenance schedule.
Regular oil changes and other routine maintenance tasks can help prevent car shaking at idle.
2. Use High-Quality Fuel
High-quality fuel can improve your car's performance and prevent shaking at idle.
Low-quality fuel can lead to clogged fuel injectors and other engine problems, which can cause shaking.
3. Check Spark Plugs
Worn or faulty spark plugs can cause your car to shake while idle. Check your spark plugs regularly and replace them if necessary.
4. Clean Air Filter
A dirty or clogged air filter can make the engine run roughly, leading to shaking. Clean or replace your air filter regularly to prevent this issue.
5. Avoid Overloading Your Car
Overloading your car can cause excessive strain on the engine, leading to shaking at idle. Make sure you stay within the recommended weight limits for your vehicle.
6. Drive Smoothly
Avoid harsh braking, sudden acceleration, and sudden stops. These actions can stress your car's engine and suspension system, leading to shaking at idle.
What To Do If The Problem Persists
1. Take Your Car to a Mechanic
If the quivering continues after you attempt diagnosis and repair, it is time to take your automobile to an experienced technician.
This specialist can administer an extensive diagnostic assessment to pinpoint the origin of the problem and deliver a reliable solution.
2. Get a Second Opinion
If you have already taken your car to a mechanic and the shaking persists, it may be worth getting a second opinion from another qualified mechanic.
They may be able to identify a different underlying cause that the previous mechanic overlooked.
3. Check Your Warranty
To ascertain if any expenditure will be necessary, consult the warranty agreement to examine if the shaking at idle is included and familiarize yourself with the essential steps needed to rectify the situation.
4. Research the Issue
Conduct online research on resources related to the exact automobile make and model if a distinct issue with the car is present. Take, for example, vibrations when the vehicle is idle.
Perusing discussion boards or posts associated with that particular vehicle can help determine if other drivers have experienced similar difficulties and the methods used to address them.
5. Contact the Manufacturer
If you have exhausted all other options and the shaking at idle persists, you can contact your car's manufacturer to see if they can provide additional support or guidance.
