Last Updated on June 19, 2023 by Henry T. Hawkins
As the weather heats up, many drivers turn on their car’s air conditioning to cool down while on the road. However, some may notice an unsettling vibration or shaking in their car when they turn on the AC. This can be frustrating and even concerning, as it may indicate a problem with the car’s components. In this post, we’ll explore some common reasons why cars vibrate when the AC is turned on and what you can do to address the issue.
Why Does My Car Vibrate When I Turn On Ac?
There are several common reasons why your car might vibrate or shake when you turn on the AC. Below, we have listed some common causes for this issue and their corresponding solutions.
Faulty AC Compressor
A faulty AC compressor can cause the car to vibrate when the AC is turned on. In this case, the compressor needs to be replaced.
Defective Fuel Injector
If the engine vibrates when the AC is on, it may be due to a defective fuel injector. Replacing the fuel injectors may be necessary to fix the vibrations. Additionally, a rough idle when the AC is on could also result from a faulty fuel injector.
Bad Spark Plugs
Old or damaged spark plugs can also cause the car to vibrate when the AC is on. In this case, the spark plugs will need to be replaced.
Broken or Worn out Motor Mountings
Motor mountings, also known as engine mountings, are essential components that keep a vehicle’s engine securely in place and dampen vibrations caused by the engine’s operation.
Motor mounts hold the engine in place and prevent it from vibrating excessively. If the engine mounts are broken or worn out, the car may shake when the AC is turned on. In this case, the bad motor
Faulty Throttle Position Sensor and Mass Airflow Sensor
The throttle body supports the air-flowing system in your car’s engine.
If these sensors are faulty, the car may vibrate when the AC is turned on. In this case, the sensors will need to be replaced.
Loose or Disconnected Hoses
If the hoses that connect the AC system to the vehicle engine are loose or disconnected, the car may vibrate when the AC is turned on. In this case, the hoses will need to be tightened or replaced.
Dirty Throttle Body
A dirty throttle body can also cause the car to vibrate when the AC is turned on. The throttle body will need to be cleaned if this is the cause of the vibrations.
Excessive Load on Engine
The AC system puts an extra load on the engine. If the engine is already weak or has low power, the additional load from the AC system can cause the car to vibrate when the AC is turned on. In this case, the engine may need to be repaired or replaced.
Low Refrigerant Levels
Insufficient refrigerant can result in compressor overload, causing the car to shake when the AC is activated. Conducting a leak check and cleaning the AC unit may offer a resolution. If these do not help, the refrigerant levels must be topped up.
Adjustment of Engine Idle Speed
When the AC is turned on, the engine speed increases slightly, which can cause the shaking to stop. Increasing the engine idle speed can also help stop the shaking. In many modern cars, the idle speed can be adjusted in the car’s computer.
Also read: Is it normal for a car to smell like burning
How to Fix Car Shakes When AC Is On?
Here is a step-by-step guide to fixing a car that shakes when the AC is on:
- Open the hood of the vehicle and locate the throttle body.
- Inspect the throttle body carefully for any signs of dirt or debris buildup.
Ask a partner to turn the car key to the “ON” position without starting the engine. - Have your partner press the accelerator slowly while you observe the throttle body.
- Spray a throttle body cleaner onto a clean cloth.
- Use the cloth to carefully clean the throttle body carefully, making sure to remove any dirt or debris buildup.
If a dirty throttle body was the cause of the shaking, the issue should now be resolved if the shaking persists, it may be due to a faulty AC compressor. In this situation, the AC compressor will require replacement. You should consult with a professional mechanic to diagnose and repair the issue if cleaning the throttle body does not resolve the problem.
How Do You Know When Your Car AC Needs To Be Recharged?
There are several signs to look out for that indicate that your car’s air conditioning (AC) system needs to be recharged. These signs include loss of cooling capability, warm air blowing from the in-cabin vents, a visible leak, and the AC clutch not engaging.
Here is a more detailed answer:
Loss of Cooling Capability
If your car’s AC system is not producing cold air, it may be a sign that the refrigerant level is low and the system needs to be recharged. This is one of the most obvious symptoms of a system that needs to be recharged.
Warm Air Blowing from In-Cabin Vents
Another sign that your car’s AC system needs to be recharged is when warm air blows from the in-cabin vents instead of cold air. This clearly indicates that the system is not functioning correctly and needs to be inspected by a professional.
Visible Leak
If you notice any signs of a greasy coating on any AC fittings or parts, it could indicate that the refrigerant is being lost. This clearly indicates that the AC system needs to be recharged as soon as possible. The refrigerant will continue to leak until the system stops working altogether.
AC Clutch Not Engaging
The AC clutch on your compressor engages whenever you turn on your air conditioner, and it usually sounds like a small click. The clutch relies on the pressure of the system to engage on most vehicles. If the refrigerant is too low or too high, the vehicle may not allow the compressor clutch to engage. This is a clear sign that your AC system needs to be recharged.
Also read: What is the safest speed to drive your car
Frequently Asked Questions
If your car vibrates when you turn on the AC, it’s a good idea to have it checked out by a mechanic. They can diagnose the issue and determine whether there’s a problem with the AC compressor, condenser, or engine mounts. From there, they can recommend the appropriate repairs to get your car running smoothly again.
While you can continue driving your car if it vibrates when you turn on the AC, it’s generally not a good idea. Vibrations can indicate underlying issues that could lead to more serious problems if left unchecked. Additionally, the vibration can be a sign of reduced fuel efficiency or other issues that could make driving less enjoyable.
While you can continue driving your car if it vibrates when you turn on the AC, it’s generally not a good idea. Vibrations can indicate underlying issues that could lead to more serious problems if left unchecked. Additionally, the vibration can be a sign of reduced fuel efficiency or other issues that could make driving less enjoyable.
To prevent your car from vibrating when you turn on the AC, it’s important to keep up with regular maintenance. This includes having your AC system inspected and serviced regularly to ensure that it’s in good working order. Additionally, keeping your engine mounts, air conditioning compressor, and fuel injectors in good condition can help prevent vibrations and other issues from occurring.
Conclusion:
If your car vibrates when you turn on the AC, it’s likely due to one of the reasons we’ve discussed in this post. While some issues may require a professional mechanic to diagnose and fix, others can be resolved with simple maintenance tasks or adjustments.
Remember to regularly maintain your car’s AC system, including changing the air filter and refrigerant, to prevent vibration and ensure smooth operation. These steps allow you to enjoy a cool and comfortable ride without any unwanted shaking or vibrations.
