Reasons why your engine vibrates when you put your car AC on


Posted by: Oluwaseun Adeniji

Share this post:

Latest news articles

Do not make the mistake thinking the only reason your car engine vibrates when you turn your A/C on is because there is a problem with your ac compressor. Read here for other possible causes!

When you are faced with the dilemma of a vibrating engine whenever you activate your car air conditioner, then that could be an indicator of an impending big electrical or mechanical fault. At times, it might just being paranoid over such a very small issue. Regardless of paying attention to any change in your engine performance will help you fix it before escalation. The following are the questions you should ask yourself when you are experiencing it:

  • When was the last general maintenance done on this vehicle?
  • What was my driving habit for the last couple of days?

When you can identify the answers to these questions and take steps to address them by doing general servicing at any trusted workshop or even perform homemade maintenance. This is a big way to go about it. Naijauto has come up with reasons you might not know that can cause vibration in car engine when A/C is on.

1. When the hoses are loosen or disconnected

This is the part you might want to consult your mechanic if you do not have much technical know-how about engine. There is need to check the hoses in case they are loosen or displaced from the mount. When you do that, tighten the loosen hoses or fix back any disconnected hoses from the mount.


Any disconnected hose should be fixed back as soon as possible

2. When the spark plugs are damaged or old

Damaged or old spark plug could also be the reason why your engine vibrates whenever you turn the A/C on, due to absence of connection during first power generation. It might just be one of the spark plugs that needs replacement as a result of broken head. Endeavor to replace it accordingly and appropriately.

>>> Car AC compressor plays an important role in AC operation. See Car AC compressor price in Nigeria, when & how to replace compressor!

3. When the engine mount is worn out

One reason you or your mechanic might overlook and could cause vibration is when the engine mount is worn out or bad and possibly needs replacement. There is also possibility that in the process of repairing your car, your auto mechanic might forget to couple it back to the engine. You should probably take it to another mechanic for a thorough check up.

How to diagnose a bad engine mount in your car

4. When the internal engine is damaged

This is definitely not the kind of reason or problem you want to hear considering the financial implication and the time it will take to fix it. Do not even attempt to solve this on your own except you have a very sound technical skill and experience in engine repair. Though it is rarely the reason why your engine vibrates when you turn on the A/C but if it is, make sure you fix it quickly.

5. When there is problem with the air flow sensor

Another component you need to pay attention to when you are encountering vibration in the engine is the air flow sensor. This is due to the heavy reliance on it by the engine and A/C compressor to work effectively.

>>> What does each type of sensor do in your car? See answers here: 7 car sensor types used in modern automobile engines

6. Problem with the fuel injector

Since it is the job of the fuel injector to pump sufficient fuel into the engine at the required time, any problem with the fuel injector, it will deny the engine of fuel needed to run effectively and when you place the air conditioner on it, it strains the engine and starts vibrating. You should inspect the fuel injector and see if there is a fault with the fuel injector.


A damaged fuel injector might stop supplying fuel to the engine hereby reducing its performance

7. Bad AC compressors

You might probably be right after all thinking the vibration is caused by damage in the compressor. Since it draws power from the car engine to work and a problem with it might lead to vibration.

Now you know what might be responsible for that vibration in your car engine. Take a step and fix it as soon as possible. However, do not forget to check other articles in the maintenance section here on

Oluwaseun Adeniji
Oluwaseun Adeniji

Oluwaseun Adeniji

New releases

Oluwaseun Adeniji is a passionate writer and a poet with special interest in writing about cars. He is a master degree holder in international conflict and management. He enjoys feeding the public with the latest auto gist and well researched car reviews. He is also a strong football lover. So, if Oluwaseun is not writing, expect him to be reading about sports.

See more