Car Shaking When Stopped or idle (7 Causes and Solutions)

Car Shaking When Stopped or idle, You know you are having fun when you are rocking back and forth on your rocking chair. But it isn’t fun at all when you rock while you are sitting inside your car.

What does it mean by car shaking when stopped or idle?

When you sit inside your car and just start the engine, and don’t do anything else, like hit the gas, putting into gear or acceleration, your car is in idle.

When your car is in idle, it is perfectly normal for it to vibrate a little.

This is because of the essential parts of the engine that have to move when the engine starts, like timing belts and gears.

A smoothly idling engine is supposed to provide the parts with enough power for them to be able to operate steadily.

It also enables the basic systems of the car to run, like the electrical systems, the power steering or the cooling systems.

However, if it is vibrating more than normal, it means that it is about time you give your car a thorough inspection.

When your car is struggling to maintain a steady vibrational pattern when it is at idle, it is an indicator that you need to take a look at all the causes and fixes.

Causes of the car shaking when stopped or idle

Your car shaking at idle is different from your car shaking at acceleration. First of all, we have to remove the tires from the list of culprits, because they certainly serve no contribution when the car is shaking when it is stopped.

To figure out why is your car shaking at idle is a lot easier than figuring out why your car is shaking when it is being accelerated. This is because when your car is at idle, the only part that is moving is the engine.

And thus, it has to be an engine part that is causing you trouble. The good part is that due to the fact that the engine is the only problem creating thing here, you can bring all your focus towards that and nowhere else.

However, the engine is the most complicated thing about the car, so it might also be a challenge to look into it and try to figure out a solution.

However, we have got your back. Here is a list of reasons that your car may be shaking while it is at idle.

1. Clogged or dirty fuel injectors.

Problem

The fuel systems of a car experience wear and tear after a short while of being used. Their main purpose is to deliver clean air and fuel to the engine.

However, after a short while, some parts of the fuel systems start clogging due to impurities like varnish, carbon deposits, and various other sediments.

Due to these impurities, the amount of fuel being delivered to each part of the engine does not remain even. If anyone of the following components is clogged, your car is going to start shuddering in idle. This is so because the fuel is not reaching the combustion chamber uninterrupted.

·         A throttle body or carburetor

A carburetor stabilizes the amount of fuel and air that are getting inside the engine. It regulates their amount and makes sure that every engine part is getting an even amount of fuel.

·         Fuel filters

The basic function of a fuel filter is to block the dust and dirt that might be trying to enter the fuel injection line. Because once they get into the fuel injection line, they will eventually get into the engine and damage it. A fuel filter prevents that from happening.

·         Catalytic converter

A catalytic converters purpose is to regulate the emissions that leave your car.

·         Vacuum line

The air that flows through the system of the engine needs to do so at optimal pressure at all costs. A vacuum line makes sure that is the case all the time.

·         Fuel pump

The fuel pump is supposed to pump fuel to the engine.

A mass airflow sensor

The air-fuel ratio needs to be balanced before it reaches the engine of the car. If it is not balanced, the engine’s performance will be negatively affected. The mass airflow sensor is responsible for checking the air-fuel ratio the reaches the engine of the car.

Solution

In order to avoid the shuddering that is being caused by any one of these parts, what you need to do is get them all cleaned very often. If the dirt has gotten too bad, then you can also get them replaced.

An effective solution will be using a fuel injector cleaner. You can also clean the throttle body. The throttle body can be cleaned by the throttle body cleaners.

2. Dirty or worn out spark plugs

Problem

This is one of the most common causes of the car shaking at idle. If your spark plug is dirty, the dirt and debris buildup inside it is not going to let the spark plug ignite the fuel as it won’t be able to fire properly.

A spark plug is supposed to light the fuel that is present in the piston cylinders of the engine if it is worn out, the ability of the spark plug to transmit the electricity needed for creating sparks.

When it is not able to create sparks, the engine cylinders will not be ignited, and the engine’s efficiency will be affected.

This can be a cause of both, the car shaking at idle or while accelerating.

Solution

You can solve this issue by replacing the spark plug if you haven’t done that recently. If you have, you can also clean them out for the sake of a better performance.

Spark plugs have a relatively short life span. If you are a do-it-yourself kind of person, you will be able to change them inexpensively. However, as there are many types of spark plugs, make sure you are getting the one that is suited to your desires.

If you want to keep in mind the exact specifications, make sure to look into the owner’s manual. The spark plugs that suit you may be different from the ones your colleague brags about.

If you are not do-it-yourself, pay a visit to your mechanic. He will make sure to install and calibrate the spark plugs that you need correctly.

3. Fault in the vacuum hose

Problem

The main purpose of a vacuum hose is to emit the exhaust fumes from your engine. If your vacuum hose is cracked or worn out, your engine will be deprived of proper clearance of the fumes it releases.

This inefficient clearance produces an imbalance of the air-fuel ratio, which prevents the smooth operation of your engine.

A damaged vacuum hose will make your engine lose its power, stall and then misfire. This issue often goes overlooked, but it happens way more than you think.

While you are driving, the vacuum hose tends to pop off, or you or your mechanic could accidentally disconnect it while you are working in your car.

A hose coming loose is going to cause violent shaking when your car is in idle. If there is a crack inside your hose, there will still be shaking, but a lesser amount of it.

Solution

The solution for this problem is to check all the connection of the hose and se if they are securely connected. If you feel like a hose is loose, it is time to replace it. Because even if you secure a loose vacuum hose, it will come off again and cause problems.

If there are any small air leaks, you will have a hard time finding them. To check them, you can spray soap water along the hose while the engine runs. In case of a crack, the crack will be sealed temporarily by the soapy water, and the sound of the engine vibration will be dulled temporarily.

Moreover, you need to get your hoses inspected by your mechanic every now and then, if you want to prevent severe damage to your engine from them.

4. Cracked or torn timing belt

Problem

If the timing belt is torn, cracked or stretched, your car is going to shake while idling. A damaged timing belt indicates that your timing belt is going to fail to function very soon.

The earlier you get this warning sign, the better it is. Because if your timing belt breaks completely, it is going to cause a major amount of damage to your car.

Solution

It is extremely important that you strictly follow the manufacturer’s guidelines when it comes to the length if intervals between timing belt replacement.

It may not be very cheap to replace a timing belt, as with the timing belt replacement also comes the water pump replacement.

But if you do not get it replaced on time, it might cause you thousands of dollars of damage.

5. Contaminated air filter

Problem

An engine’s air take is going to be interrupted if the air filter is clogged, or dirty. When the air filter is not functioning smoothly, the combustion chamber does not get enough air. Which means that the amount of fuel that is being injected becomes insufficient.

This will cause your car to not only shake violently when in idle, but it will also make it stall, and the car would need to be restarted.

A dirty air filter can be one of the causes that your car is vibrating during idle.

Solution

Fortunately, you can replace a car air filter yourself, and it is not going to cost you a lot of money. An air filter, on average, costs about $10-$20 on average.

You can also purchase a renewable filter. So that you will not have to replace it every time it is clogged. You can pop it out, clean it, and then put it back in again. Upfront, it may look like it costs you much, but it will be a money-saving purchase in the long run.

Read Also: Car Shaking When Braking at High Speeds

6. Bad motor mounts

Problem

One of the roles that a motor mount is supposed to play is to dampen the vibration of the engine so that the people sitting in the car do not feel it.

If the motor mount is broken, you will get to know that in no time, as the damaged one makes itself known immediately.

A damaged engine mount will be more noticeable when the engine is onto more vigorous activities, like when you are driving.

However, you may also notice shuddering or rattling of the engine while it is at idle.

Solution

If you even slightly suspect that there might be an issue with your motor mount, you need to take it to your mechanic immediately.

You mechanic will confirm the issue and replace the mount as soon as possible. If the mount is not replaced as soon as it can, the other engine mounts are going to fail along with it, and the damage is going to flow to many other parts of the engine.

For example, if the motor mount is broken, the engine will be a little lower than its actual position. In that case, the blades in the radiator fan are going to hit the surrounding shroud and break.

7. Broken serpentine belt

Problem

Another reason why your car may be shaking at idle is the loose or broken serpentine belt. A serpentine belt is different from a timing belt.

A serpentine belt is responsible for controlling the cooling system of the engine.

This belt is present to make sure that the cooling system of your engine is operating normally and smoothly. If it breaks somehow, your engine is going to show you signs by making distinct noises.

If you do not get it checked in time, it is likely that your engine breaks down completely in a while and shuts down.

Solution

It is extremely important that you go down to your mechanic’s and have him check your belts every now and then. He will see if your belts are adjusted and operating correctly.

Such regular checkups are going to make sure that the problem is pointed out before it becomes too big and in turn, damages your vehicle.