Why Does My Car Shake When I Turn the AC On?

Does your car shake when the AC is on? This could be as a result of several things. Not all of them problems. Some of them can be remedied by a simple solution. In some case you can even handle them with not specialized tools. Which ends up saving you money.

Keep reading to learn how to stop your car from vibrating car when you turn the ac on.

What causes vibrations with ac compressor on?

Here are the reasons your Car jerks when AC is on;

Strained Engine

The AC acts as a small engine, and it puts too much stress on the engine. When you turn the AC on, the vehicle engine triggers elements such as idle speed or air control motor. You can increase the idle compressor by compensating with an additional drag. The inaccuracy in this process causes the car to shake when AC is on.

In most cases, the additional drag can lead to the steering wheel vibrates when ac is on. This increased strain on the engine could cause parts of the engine to wear out. In turn, this leads to the vibration or shaking of your car when the air conditioning is on.

This happens when the AC compressor strains the engine. More severe shaking can mean that the damage is also more severe. When you notice this shaking, bring your car to an air conditioning technician as soon as you can.

If this goes untreated, the strain on the engine will continue to worsen. As the vibration grows more severe, the damage is becoming a bigger issue. This shaking can even lead to complete engine failure of your vehicle if untreated.

When you turn the steering wheel with the AC is on the chances of engine stalling increase. If the AC continues loading the engine, some engine parts will wear out, eventually needing replacements.

Worn out Engine Foundation/ Mounting

The engine mountings hold the suspension and engine into place. The mounts hold the engine and transmission at the right suspension angle. When you turn the Ac, the mounts go through a lot of strain. Therefore, when the engine mounts or foundations wear out, you will experience vibrations and shakes when the AC is on.

If the engine mount is broken, the vibrations will increase, and noises will accompany them. Therefore, when you start experiencing the vibrations, call your mechanic to check if the mounts are in order or need to be replaced.

Loose Mountings or Foundation

A less severe cause could be loose mountings on your engine or the foundation. While this is “less severe” in terms of the damage it causes to your engine, loose mountings can lead to other issues. An insecurely installed engine could cause intense damage or an engine failure, especially while driving.

While this isn’t a direct cause of your air conditioning, this can be caused by increased stain. Regardless of your AC, you need to fix it.

A simple investigation can help decide if there are any issues. It’s best to bring it to a mechanic to check your engine’s mountings. This can require jacking up the car or possibly removing parts. What exact tasks this entails ultimately depends on the make and model of the vehicle.

A skilled mechanic can let you know if loose mountings or foundations are causing the shaking. They can also inform you of any other issue that might cause the shaking. Most times when these issues arise, you’ll need to take it to a mechanic regardless, so it’s a good first solution to find the problem.

Faulty AC Compressor

One issue that doesn’t have to do with the engine directly is your air conditioning compressor. A faulty AC compressor can cause your entire vehicle to shake violently.

Like with loose mountings, the best way to detect this issue is to simply look. A good trick is to accelerate your vehicle with the air conditioning on or off. If the shaking is significantly worse with the AC on, there is a high chance you have a faulty AC compressor.

Of course, this isn’t a fool-proof way to diagnose the problem. Even if this test seems to hint at the issue being your air conditioning, you should still have a professional check it out. That way you know for certain, instead of spending time and money replacing your compressor and finding out it wasn’t the issue.

Failing AC System

While a compressor is a likely cause, it’s far from the only component of your air conditioning system. These systems are complex and can have any number of things go wrong with them. Many of these malfunctions can cause vibration and shaking in your car.

For example, clogged or leaking hoses can struggle to properly get air and coolant through the system. This can cause them to shake, with the vibration directly affecting your car.

A good way to fix this is to work proactively. Having your car undergo regular maintenance can help to fend off issues with a failing air conditioning system. This is more important in climates where the AC is running constantly or in older cars.

Malfunctioning Throttle Position Sensor

One specific component of your air conditioning system that can undoubtedly cause shaking is your throttle position sensor. This is one of the pieces responsible for regulating the RPM of your air conditioning.

If this piece is faulty or malfunctioning, the RPM of your AC is going to vary wildly. This can cause your car to shake with a constantly-changing RPM.

The best way to fix this is to clean or replace your throttle positioning sensor. Checking this piece is also an important part of the regular tune-up for your car. If this piece is functioning perfectly, your issue is likely somewhere else.

A faulty TP sensor does not control the RPMs. Therefore, when you turn the AC and the RPMs are inconsistent, this will lead to the car idling rough with AC on. To solve this issue, you need to clean the sensor or have it replaced.

Faulty Fuel Injector

The fuel injector pumps sufficient fuel into the engine at the right time. If the fuel injector is malfunctioning, the engine will not get enough fuel, reducing its effectiveness. When the AC is on, it strains the engine further, and the vehicle starts vibrating. If this is the cause of the vibrations, then the fuel injectors will need to be replaced. 

Damaged or Old Spark Plugs

A damaged or old spark plug is the other reason why your Honda Accord shakes when the ac is on. This is caused by a lack of connection during the initial power generation. This could even be as a result of one worn-out or broken spark plug. In this case, the plugs in question need a replacement immediately before they lead to further damages.

Increased Pressure

AC compressor puts a strain on the engine and in a situation when the pressure goes above 400 PSI, it eventually leads to vibrations. If the pressure continues to increase, some parts of the engine can wear out ultimately. However, some other reasons may include the issue in a cooling fan or some blockage in the AC system. In such condition, you can either use some fail-proof maintenance tips or take your car to the nearest mechanic store as soon as possible.

Additional Car Shaking Reasons Associated With AC

There are additional reasons which most commonly include:

  • Faulty compressor bearings (these wear out over time with use)
  • Clogged condenser coils that can’t dissipate heat properly due to not being cleaned regularly enough
  • A dirty evaporator core causes insufficient airflow through the system which causes less cooling capacity and creates more noise than normal operation would produce when everything is working right!

The best way to determine the root cause of your specific issue is by taking it to a professional mechanic for diagnosis and repair.

How to Fix Car Shakes When AC Is On

The most common cause of AC that makes cars idle rough is a dirty throttle body. In this case, follow these steps fix rough idle when AC is on:

  • Open the vehicle hood
  • Check the throttle body carefully
  • Ask a partner to turn the car key to the “ON” position. They should not start the engine.
  • Ask the perform assisting to press the accelerator slowly
  • Spray a throttle body cleaner on a clean cloth
  • Use the cloth to clean the throttle body carefully

If a dirty throttle body was the cause, then you will have fixed the issue. In some cases, this problem would be due to a faulty AC compressor. In this case, you will be required to change and replace the AC compressor.