Reasons Car Shakes When AC Is On: Driving Discomfort

car shaking

Have you ever noticed your car shaking when you turn on the AC? It can be a bit unsettling, right? Well, there could be a few reasons behind this.

For instance, your engine might be working overtime to power not just the compressor, but all the other parts of your car too. This extra effort can lead to those pesky vibrations.

Or maybe, the culprit is a worn-out belt or a faulty compressor. Either way, it’s crucial to address these issues promptly to prevent further damage.

Now, let’s not forget about the cooling fan. If it’s unbalanced or damaged, it could be causing your car to shake.

Picture this: if the fan blades are bent or broken, the airflow won’t be even, and this imbalance can create vibrations. And what about a blocked condenser or evaporator?

They could also mess with the airflow, making your AC system less effective and causing your car to shake. Lastly, let’s talk about refrigerant – the lifeblood of your system. If there’s not enough of it, the compressor might struggle to run smoothly, leading to those unsettling vibrations.

So, it’s a good idea to check for refrigerant leaks and keep up with regular maintenance to ensure works like a charm. So, next time you feel your car shaking when the AC is on, remember these potential causes.

And don’t worry – with a bit of attention and care, you can keep your car running smoothly, even on the hottest of days!

The Underlying Issue

When your car shakes as you turn on the AC, it’s a clear indication that something is amiss. Many people assume that this is solely due to an issue with their AC compressors, but there could be several different factors at play. Let’s explore these in detail.

Potential Causes

This is a compilation of potential factors that could be causing this issue.

Damaged AC Compressor

The AC compressor plays a crucial role in cooling the refrigerant before it’s sent to the condenser. A faulty compressor puts undue pressure on the engine, leading to shaking. If the AC compressor fails, it can strain your car engine and cause your car to shake when stopped and the air conditioner is on.

Load on Engine

Turning on the air conditioner activates components such as idle speed and air control motor by the vehicle engine. High-tech insulation and forced induction (compressor) systems can put extra strain on engines, resulting in vibration when the load exceeds a certain limit.

Defective Fuel Injector

fuel injector bad

A faulty fuel injector can cause additional strain on your engine, which can result in shaking when the car air conditioner is on. The fuel injector’s job is to spray and control the flow of fuel, working with electronically controlled valves.

Bad Spark Plugs

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 your engine mounts are broken, misaligned, or worn out, they can put a strain on the engine and consequently make it shake when air conditioning is turned on.

Bad Throttle Position Sensor

A bad throttle position sensor (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

A loose or disconnected hose interrupts the flow of your car’s air conditioning system, causing vibrations from the engine.

Dirty Throttle Body

The throttle body maintains the air-flowing system in your car’s engine. A dirty throttle body results 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 to Fix the Issue

AC car

Depending on the cause, there are different ways to fix the issue. If the culprit is a dirty throttle body, you can clean it by following these steps:

  1. Shut the car engine off
  2. Pop the hood
  3. Inspect the throttle body for dirt
  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 problem is due to a faulty AC compressor, it would need to be replaced.

Frequently Asked Questions

What does it mean if the shaking gets more severe when the AC is on?

More severe shaking could indicate that the damage is also more severe. For instance, a severely damaged AC compressor can put an excess load on the engine, leading to more noticeable shaking.

What can I do to fix the shaking?

The solution depends on the cause of the problem. If the issue is due to a faulty AC compressor or a worn-out serpentine belt, these components may need to be replaced.

If the engine mounts are damaged, they will need to be repaired or replaced. It’s best to have your car inspected by a professional mechanic to accurately diagnose and fix the problem.

Can a vacuum leak cause my car to shake when the AC is on?

Yes, a vacuum leak can cause your car to shake when the AC is turned on. If the engine is idling and you get a constant “shudder” or shake when the AC is on, it could be due to a vacuum leak.

Can a clogged condenser coil cause my car to shake when the AC is on?

Yes, clogged condenser coils can also cause your car to shake when the AC is on. These coils can get clogged over time, which can affect the airflow and cause your car to vibrate.

Is it safe to drive when my car shakes?

It is best to have your car checked by a qualified mechanic if it shakes with the AC on. While it may not be immediately dangerous, the shaking can indicate underlying problems that could worsen over time.


Car shaking with AC on? Multiple factors can be at play.

Worn-out or imbalanced engine mount can cause vibrations throughout the vehicle. A faulty compressor or clutch can also cause abnormal vibrations.

A cabin air filter that is dirty or blocked can impose stress on the system and result in shaking. Swiftly addressing these problems is crucial.

Additionally, electrical inconsistencies caused by alternator failure can disturb the engine and lead to a shaky journey when using the AC. If you are interested in distinguishing between a faulty car battery and a malfunctioning alternator, we recommend reading our article.

Refrigerant insufficient in the system can overwork it, causing vibrations. Regular maintenance and inspection can help prevent such issues.

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