Here you will become acquainted with basic faults that are causing car shakes when AC is on and decreasing the capabilities of various internal parts of the engine.
When your car starts shaking while the AC is on, it’s time to discover the culprit. There could be assorted reasons why this dilemma has appeared in your car, but major causes are essential to be found.
Contents
- Top Reasons Why Car Shakes When AC Is On
- Car Vibrates When AC Is On: How To Fix The Problem?
- How To Prevent The Car Shakes When AC Is On Issue?
- FAQs on Car Shakes When AC Is On
- Why does my car shake only at red lights when the AC is on, but not while driving?
- Could bad motor mounts make my car shake more with the AC on?
- Is that normal if a hybrid car shakes when the AC is on?
- Is shaking during AC use more common in older cars than new ones?
- Does the type of refrigerant used in the AC system affect engine shaking?
- Final Words
Top Reasons Why Car Shakes When AC Is On
Car shaking, while AC is on, is one such dilemma that can happen anywhere and anytime. Therefore, it’s preferable to know the cause of this problem.
After all, no one wants to deal with a much bigger issue, which can be fixed as soon as it has happened. So, let’s delve deeper into the causes of why the car vibrates when the AC is on below.
Failed AC Compressor
The AC compressor is a smaller engine in itself and puts a lot of stress on the car’s engine.
When you turn on the vehicle AC, the engine triggers some elements, like the air control motor or idle speed, so that the idle compressor can be increased by compensating with extra drag.
In a situation where the car shakes when AC is on, inaccuracy in this process could be the reason behind it. In many cases, additional drag can result in vibrating idle and in fact, the engine stalling.
When the steering wheel (especially the power steering) is turned while the AC is on, the chances of engine stalling become higher. Increased shaking could be the result of broken motor mounts too. So, look for this issue!
See More: Why Does a Car Shake When Turned On? Find It Here

Increased Pressure
An 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 with a cooling fan or some blockage in the AC system.
In such conditions, you can either use some fail-proof maintenance tips or take your car to the nearest mechanic store as soon as possible.
Shabby Engine/ Transmission Mount
The mounts go under a lot of strain every time you turn on the AC, which can cause the car vibrates when AC is on.
Each mount plays its role to keep the transmission and engine in place to uphold a proper suspension angle. It also keeps wiring, hoses, and isolation from vibration or noise in place.
Hence, any issue in the mount will result in shakes or vibrations. The broken mount can lead to increased vibration and noises especially when the compressor of AC puts pressure on the engine.
Therefore, check your mounts to resolve this issue.

Loosed Hoses Connection
Loosen or disconnected hoses are a common cause of vehicle vibration when you turn on any electric function related to an engine, such as the air conditioner. Loose hoses disrupt the flow of the condition system.
Keep in mind that any electrical problem, no matter how minor or major, might disrupt the car’s correct smooth operation and stability control.
Excessive Engine Load
The AC compressor works with the engine and exerts load on it. There is a load limit that the engine can withstand, and over it produces failure.
To stress the engine, it is required to provide restricted pressure to it and maintain a particular difference.
If the load on the engine is excessive, it may cause some parts of the engine to wear out. It does, however, produce a clog in the AC system that can only be handled by a professional.
Faulty Fuel Injector
The fuel injector is extremely vital in the engine. It is used in engines to spray gasoline and regulate the flow of fuel. It uses electronically controlled valves to allow them to open and close several times per second.
A faulty fuel injector increased engine pressure, causing the car to vibrate with air conditioning.

Failed Spark Plugs
An explosion of air and gasoline is used to inject spark plugs, which provide electricity for the automobile engine.
Damaged spark plugs are unable to act correctly and create vehicle vibration when the AC is turned on.
Moreover, the broken spark plugs never supply the correct energy and power, causing the automobile to vibrate and damaging the engine. If you discover an issue with the spark plugs, replace them.
Filthy Throttle Body
The throttle body keeps the air-flowing system in your car’s engine running smoothly. However, it is an air-passing component that gets filthy rapidly, causing automotive engines to lack enough airflow.
As a consequence, when you switch on the car AC, it rattles because it is unable to acquire adequate airflow.
Car Vibrates When AC Is On: How To Fix The Problem?
Your solutions to solve car vibrates with ac on issue will be dependent on your specific situation, but there are simple approaches to diagnose each.
The vibration is an evident indication that is typically traceable through trial and error.
If your car doesn’t shake when the air conditioning is turned off, for example, your AC is most likely to blame.
Bringing your car to a skilled specialist is the best approach to fix or diagnose any problem. The best place to start is with air conditioning repair services or a local technician.
Allowing specialists to handle it increases the likelihood that the diagnosis will be more certain and the remedy will be more successful.

Work carefully and have a backup plan if you’re hands-on and know what you’re doing. You always face the danger of not having the right equipment or enough hands to do the job properly.
Keep a mechanic in mind in case you need to bring your vehicle in, and avoid driving a vehicle that is excessively shaking for safety reasons.
How To Prevent The Car Shakes When AC Is On Issue?
A/C System Maintenance
Regularly servicing your A/C system includes checking the refrigerant level, inspecting components for leaks or damage, and cleaning or replacing the cabin air filter.
By addressing minor issues in advance, you can save money and hassle in the long run and keep your car running smoothly, even with the A/C blasting on a hot day.
Engine Tune-Up
A well-maintained engine is less susceptible to car vibrate when AC is on, even under the added load of the A/C compressor.
A tune-up not only improves engine performance but also optimizes fuel efficiency and reduces emissions.
Follow your vehicle maintenance schedule for tune-ups to prevent potential problems later on.
Check Engine Mounts
Inspect your engine mounts for cracks, tears, or excessive softness. Replacing worn engine mounts can significantly reduce vibrations and restore smooth operation.
Engine mounts act as shock absorbers, isolating the engine’s vibrations from the rest of the vehicle.
Replacing worn mounts not only reduces vibrations but also prevents potential damage to other engine components.
Inspect the A/C Compressor
The A/C compressor is the heart of the air conditioning system. So you should have a mechanic inspect the compressor for any signs of damage
In some cases, replacing the compressor might be necessary to resolve the shaking issue.
Clean the Condenser Coils
The A/C condenser, located in front of the radiator, releases heat absorbed by the refrigerant.
Dirty condenser coils can restrict airflow and cause the A/C system to work harder, potentially leading to increased engine strain and vibrations.
Cleaning the condenser coils periodically can improve A/C efficiency and reduce the likelihood of shaking.
Cleaning the coils with a gentle stream of water or compressed air may restore proper airflow and improve the overall efficiency of the system.

FAQs on Car Shakes When AC Is On
Why does my car shake only at red lights when the AC is on, but not while driving?
At idle, the engine has the least power reserve. If the AC compressor kicks in and the idle air control valve (IAC) or throttle body is dirty, the engine may stumble, causing noticeable vibration.
Could bad motor mounts make my car shake more with the AC on?
Absolutely. When the AC compressor turns on, it creates torque that puts extra stress on worn engine mounts, making vibrations more noticeable.
Is that normal if a hybrid car shakes when the AC is on?
In some hybrids, the AC compressor runs on an electric motor and can cause the gas engine to turn on more frequently.
If that handoff is rough or unbalanced, it can result in shaking.
Is shaking during AC use more common in older cars than new ones?
Yes, because newer cars have more advanced idle stabilization systems.
Older vehicles are more likely to reveal issues like dirty IAC valves or aging compressors under AC load.
Does the type of refrigerant used in the AC system affect engine shaking?
Unlikely, but if the system is overcharged or undercharged with refrigerant, the compressor may strain, and this load imbalance can cause vibration in car when AC is on.
Final Words
Having an issue isn’t something to worry about, not doing anything about it is the foremost concern.
So use these maintenance tips and check for the suspected parts whenever a car shakes when AC is on.
That’s the way; you can make the vehicle durable and enhance your driving experience!