Many people experience their car shaking when they turn on the air conditioning (AC). There are several reasons behind this, and shaking can occur at any time. The most important thing to remember is that these vibrations usually aren’t anything to worry about. Still, it is vital to know why it is happening to distinguish it from serious problems that can arise.

The Common Causes of Shaking When the AC Is On

If there is a mechanical or electrical fault, it may cause your car to start shaking. You can assess this by doing general maintenance of your vehicle and identifying your recent driving habits if it is the first time the shaking occurs.

Increased Engine Load

You can think about the AC as a small engine, so when it starts running, it puts a lot of strain on your car’s engine. A control unit affects different processes to compensate for this additional load. When it fails to restore the balance appropriately, it can cause a shaky idle and even result in your engine stalling.

Sometimes the components get dirty, and your control engine unit can’t do a proper job balancing. If the additional load goes too high, it can lead to different levels of vibrations. This overload is primarily the problem in older models with worn-out parts. It can also point out to AC blockage or a faulty cooling fan.

Faulty AC Compressor

A faulty compressor can be a reason for an increased load on your engine that leads to vibrations. You can test your car by accelerating with and without the AC and see how it compares. If there is a drastic difference, your AC compressor may need replacing.

Fuel Injector Problems

Your car’s engine needs a steady supply of fuel, and a fuel injector is a part responsible for this job. If there is an issue with the fuel injector, it may only show when you put the AC on. So, make sure to inspect it and determine if it’s the cause for the vibrations your car is experiencing.

Weak or Broken Motor Mounts

Motor mounts play a vital role in keeping your engine and suspension in place. It is crucial for proper engine functioning, and these parts sustain a lot of pressure. And when you turn the AC on, you increase the engine load, which puts more strain on mounts, leading to your car shaking if they are weakened or broken.

Keep in mind that engine mounts wear out over time, so if you drive an older model and are close to that 100,000 miles mark, you should check your mounts to make sure they are not causing these vibrations.

Should You Go to the Mechanic?

If you know your way around cars, you know that a bit of shaking when your AC is on is usually not a big deal. You can look at some of the possible causes or take your car to the mechanic if you believe that there is a serious underlying problem with your vehicle.