Reasons Why Your Car Shakes When AC Is On (Simple Fix!)

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car shakes when ac is on

You’re driving on a hot day and notice that your car shakes when the air conditioning is turned on.

Your car shaking when AC is on may seem like a small problem but it’s definitely not something you want to ignore.

When your car shakes when the AC is on, it’s a sign that something needs to be done about the problem. Most people think this happens only due to an issue with their AC compressors but there could actually be several different things happening here which we will discuss in this article.

So fasten your seatbelts and let’s jump in!

What causes car shakes when AC is on?

Air conditioning is a basic feature in all new vehicles. The air conditioning has two primary functions: raising refrigerant pressure and creating low-pressure that enables vaporization, which absorbs heat energy from your car’s cabin to make it comfortable for you while driving around.

Your car’s AC system works to cool down your vehicle, but the process isn’t always easy. The refrigerant in the air conditioner must be hotter than average temperatures for heat transfer and circulation – which means there are some times when it’s more difficult than others!

If your car’s AC compressor and motor mounts aren’t working properly, they might put strain or pressure on the engine when you turn the AC on, causing it to shake or vibrate.

Here are some common reasons why your car may shake when the AC is on:

Damaged AC compressor

A faulty AC compressor puts pressure on the engine and may lead to shaking. If your AC compressor is damaged, it won’t be able to function effectively.

The refrigerant is cooled by the compressor before being sent to the condenser. That is why if the AC compressor fails, it can put a strain on your car engine and eventually make your car shake when stopped and the air conditioner is on.

When an engine is idling for a long period of time, it can cause excessive drag. Engine stalling is caused by vibrating while idle. In a car that has power steering, too much drag while the A/C is on may cause more engine stalling and greater shaking in the steering wheel.

When the air conditioner is running, accelerate the car to diagnose the issue. If you notice a difference in pick, it’s time for an AC replacement.

Load on engine

When you turn on the air conditioner, components such as idle speed and air control motor are activated by the vehicle engine. Because of the high-tech insulation, forced induction (compressor) systems put extra strain on engines and can result in vibration when the load goes above a certain limit. If the burden keeps growing, some engine components may wear out over time. However, other factors might include a faulty cooling fan or an obstruction in the AC system. In this case, take your car to the nearest mechanic ASAP.

Defective fuel injector

The fuel injector is an important part of the engine in your vehicle. Their job is to spray and control the flow of fuel, working with electronically controlled valves so they can open or close many times per second! A faulty fuel injector can cause additional strain on your engine, which can result in shaking when the car air conditioner is on.

Bad spark plugs

The spark plug generates electricity for your engine by creating an explosion from a blend of air and fuel. Damaged or outdated spark plugs might be the reason for your automobile’s vibrating when you switch on the air conditioner. If your car’s spark plug is unable to deliver the engine ignition’s power or speed, especially during the initial power production, there is likely an issue and you should have them replaced.

Worn out or broken motor mounts

If you have been noticing abnormal engine vibrations or shaking when your AC is on, the problem may be in the engine mounts. If these are broken, misaligned, or worn out they can put a strain on it and consequently make it shake when air conditioning is turned on. When you switch on the Ac, the mounts are put under a lot of stress. As engine mountings or foundations wear out, you will feel vibrations and shakes when the AC is operating. If the engine mounts breaks down, the shaking will get worse.

Bad throttle position sensor

A throttle position sensors job is to keep track of an engine’s air intake. The throttle position sensor monitors how far the throttle blade (or valve) can be opened, which is determined by how far down the gas pedal has been pushed.

A bad TPS cannot control your vehicle’s RPMs, and as a result, when the AC is turned on the RPMs do not remain consistent. This can cause your car to shake.

Loose or disconnected hoses

In some cases, the vibrations from the engine can be caused by a loose or disconnected hose. When the hose is loose or disconnected, it interrupts the flow of your car’s air conditioning system. When the car goes through periods where it has to work harder because of weather changes, you’re likely to feel vibrations and shakes when your AC is on.

Dirty throttle body

The throttle body maintains the air-flowing system in your car’s engine. The throttle body is an air-passing component that gets dirty quickly, resulting in car engines being unable to get enough airflow. As a result, when you turn on the car AC, your automobile vibrates because it isn’t able to properly obtain airflow.

How do I fix a car that shakes when the AC is on?

As we’ve learned, there are a couple of different reasons why your car engine vibrates when the AC is on. There are different ways to fix the issue depending on what the reason is. A dirty throttle body is the most common cause of AC causing your car to shake. If this is the case, follow these instructions:

  1. Shut the car engine off
  2. Pop the hood
  3. Inspect the throttle body for dirty
  4. Ask a friend to turn the car key to the “ON” position. Do not start the engine.
  5. Ask them to press down on the gas pedal slowly.
  6. Use a cloth to clean the throttle body

If the culprit was a dirty throttle body, you will have resolved the problem. This problem could also be caused by a faulty AC compressor. In this scenario, the AC compressor would need to be changed and replaced.


What causes rough idle when AC is on?

There are several causes for a vehicle’s rough idle when the air conditioner is on. The most common causes of rough idling are a faulty or dirty AIC valve, defective cooling fan or condenser, a dirty throttle body, worn out spark plugs, and damaged engine mountings. Some will just require cleaning to fix these issues while others will require replacements.

How do you fix rough idle when AC is on?

When the air conditioner is on, a rough idle indicates a problem. A dirty throttle body is the most prevalent reason. In this situation, cleaning and unblocking the throttle body will suffice. If worn-out and outdated spark plugs are to blame, they’ll need to be changed with new ones.

Will a bad AC compressor affect the engine?

The car AC compressor is not a part of the engine. The AC compressor works by compressing gas into a liquid that gets cooled to produce cold air. However, it can affect how well the vehicle idles when turned on even though it doesn’t impact the engine itself.

How can I make my car idle smoother?

The right balance of air and fuel is required for a vehicle’s smooth idle. As a result, if the air and petrol aren’t handled appropriately, you’ll get a rough idle. Rough idling can be caused by a variety of factors. To achieve a smooth rough idle, you must first identify the underlying reason of the rough idle.

I most situations, it’s due to components that control the start and fuel. As a result, it is in your best interests to inspect each of these parts one by one. Cleaning them may be beneficial if they are clogged. If the components are worn down, you’ll have to replace them.

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