Car Sputters When Air Conditioner Is On? 5 Amazing Reasons!

Are you asking yourself why your car sputters when the air conditioner is on? There are plenty of reasons as to why you are going through this problem. Car air conditioners tend to break more often because they are smaller than a traditional AC system. It may be a low refrigerant, lousy belt, failing ac compressor, and many others. If you are going through this problem, this article will help you. So, why car sputters when air conditioner is on?


car sputters when air conditioner is on

Reason For Sputter In A Car Air Conditioner When It’s On

First, recognize that this issue is not limited to a single system — it is the result of several factors. First, it strains the engine when you turn on your air conditioner (the engine controls the compressor). Which creates pressure in the system, allowing low-pressure, gaseous refrigerant to be converted into high-pressure liquid and utilized in your cooling system).

You need first to understand what happens in your AC or how it works before identifying the problem. We have gathered information about why your car sputters when the air conditioner is on? So before you call your mechanic, please read this article, “Car sputters when air conditioner is on.” And here they are:


Reason #1. Faulty IAC valve

The PCM (power system control module) uses an idle air control (IAC) valve to manage idle speed. IAC basically allows a certain amount of air to be blown out of the throttle plate. During a cold engine start, additional air improves the air-fuel mixture. It also helps increase engine speed when other requirements are placed on the engine, such as turning on the air conditioning or defrost system.

The most typical IAC problems include carbon deposits around the IAC valve, throttle passage, and IAC engine failure.

You can perform a basic IAC engine test and look for carbon deposits in the throttle bypass port and the IAC valve. You can visit this article on auto repair the electric cooling problems and serve it as a guide.


Reason #2. Dirty throttle body

If your car is idling unstable, it may be because the throttle body is dirty. The throttle body regulates the amount of air taken by the engine. When it gets dirty, the engine will not operate normally. In AC operation, a dirty throttle body could affect idle speed. And controlling the throttle plate to stay closed during idling, as the computer regulates the airflow through the throttle plate.

On the other hand, if the throttle plate and orifice are dirty, problems will occur when the air conditioner is turned on, resulting in insufficient airflow. Cleaning the throttle body can improve vehicle performance and driving performance.

This is a remedy for all people who suffer from unstable engine operation, dangerous vehicle operation, and reduced performance. At the same time, the new car is still new. When the engine is shut down, hot exhaust gases and unburned gasoline will float to the top of the engine.


Reason #3. Complications with the cooling and condenser fan

A malfunctioning cooling fan or condenser can cause high-pressure build-up and unstable idle speed. If the rate of your cooling or condenser fan is variable, make sure it is operating normally. Moreover, basic tests can help you run a quick circuit check if needed. You can also troubleshoot some fundamental cooling fan problems. To get this guide, visit this article.


Reason #4. Problems with the distributor and ignition

If you have an old car from a dealer, check the cover and rotor. The center and outer ends of the lid will deteriorate, be covered by carbon deposits, and eventually be ignited. This prevents intense sparks from being generated at the tip of the spark plug. Thoroughly inspect the manifold cover and terminals for carbon traces and cracks.

It will send voltage to the ground through carbon traces. The carbon traces on the black dispenser cover may require intense light to see. Check the lid carefully.

200~6000V outer cap terminal rotor tip if there is a little carbon deposit and wear, it is difficult to emit intense sparks. Check the rotor tip for burns, damage, and gaps. Then, replace the end as needed. Check the spark plug and spark plug wire. Inspect the rotor, spark plug wire, and spark plug repair schedule recommended by your vehicle manufacturer. If necessary, please consult your owner’s manual or vehicle maintenance manual.


Reason #5. Adjust idle speed

If you have not found the source of the problem, you may need to adjust your idle speed. You can change the idle speed on old vehicles equipped with a carburetor. In fact, many carburetors perform this procedure regularly. Adjust the idle speed screw and check the idle speed solenoid valve, depending on your model.  Then follow the steps listed in the vehicle maintenance manual.

Modern automobiles’ powertrain control module (PCM) uses input sensors to adjust idle speed depending on airflow, throttle position, and temperature. Some versions may provide manual adjustments.

Check the decals in the engine compartment or your owner’s manual.  You can check the sensors that the PCM relies on to set the idle speed. Examples include throttle position sensors (TPS), mass airflow (MAF) sensors, and also engine coolant temperature (ECT) sensors. Sensors or actuators working on the periphery of your working system may not cause problems at idle speeds before turning on your air conditioner. It may also fail to illuminate its check engine light signal.


Final Thoughts

That answers the question, why does your car sputters when air conditioner is on? Remember to check each part of your car and if you are still unsure, contact a car mechanic to help solve your problem. Do you want to read more? Have you ever wondered why an air conditioner only works when the car is moving? If yes, you can check that one out too. Nevertheless, thank you!

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