The Causes Behind Why Your Car Shakes When AC Is On

The reasons why your car shakes when AC is on is the main focus of this article. The reasons include a defective AC compressor and a strained engine.

It could also result from loose mountings and hoses or spark plug issues. Some of the possible fixes are cleaning and repairing dirty or damaged components.

10 Most Likely Reasons Why Your Car Shakes When AC Is On

The most likely reasons why your car shakes when AC is on are excessive load on the engine, failing AC system, and loosened hoses. In addition to these, other culprits are a damaged air conditioning compressor and a defective MAF sensor.

– Faulty AC Compressor

A faulty AC compressor adds more pressure to the engine, and this ends up causing vibrations in the car. The role of the compressor is to cool the refrigerant before it is sent to the condenser. If the compressor goes bad, it will cause vibrations when you put your AC on while driving.

One way to know if the compressor is the reason for your car-shaking troubles is to observe the car’s vibration. If it shakes violently (especially during acceleration), then the first thing you should suspect is your AC compressor. You can take a look at it yourself or have a professional check it out for you.

However, you shouldn’t conclude a bad AC compressor is a problem simply from how the car is shaking. Try to diagnose other things that are listed in this article as well.

– The Load on the Engine

If your air conditioning unit is putting a huge amount of load or strain on your engine, this will cause some parts of the engine to wear out and shake whenever you turn on your AC. Your vehicle’s engine has a certain max load threshold. Once the load on it exceeds this limit, vibrations may occur in the car and affect the steering wheel. If the shaking is severe, it could also mean the damage is equally severe.

Car vibrations caused by a strained or overloaded engine can be very risky because, if ignored, the damage to the engine will become more severe and lead to a bigger problem. In worst cases, it can cause a total breakdown of your vehicle’s engine. You should take your car to an air conditioning technician whenever you suspect your engine is the issue.

– Faulty Fuel Injector

The fuel injector injects fuel into the internal combustion engine. The injector also controls the flow of fuel into the engine via electronically controlled valves that can open or close several times per second. A bad or faulty fuel injector will strain your car engine, which will, in turn, cause vibrations or shaking when you turn on the air conditioner.

The injector can sometimes become clogged, thereby causing an irregular/inconsistent supply of fuel to the engine. Sometimes, the injector may fail completely, causing a sudden loss of engine power. In any of these cases, it’s best to let a professional de-clog or repair your vehicle’s injector.

– Defective Spark Plugs

A spark plug generates electricity for your engine by mixing fuel and air to create an explosion. Damaged plugs can contribute to your car’s shaking when you put on the air conditioner. The bad plugs can’t provide the engine with the needed electricity, thereby straining the engine.

Some common signs of a bad plug you can look out for are hard starting, rough idle, high fuel consumption, and engine misfiring.

– Faulty Throttle Position Sensor (TPS)

A faulty or bad throttle position sensor can also cause vibrations when driving your car with the AC on. The work of this sensor is to monitor a vehicle’s air intake. It also monitors how far the throttle valve can be opened.

A good TPS will adequately control a vehicle’s RPMs, but a faulty one will be unable to do so. The side effect of an unregulated RPM is that the AC won’t function as it should. Most ACs require RPMs of 700-900 to work properly. Running your AC at wrong or inconsistent RPMs (due to a non-functioning TPS) will strain your vehicle engine and cause shaking.

A bad TPS will also show signs like sudden engine stalling or sudden hesitation while accelerating. Most times, there’s also buckling and jerking. So if you find your car shaking and jerking or stalling while the air conditioner is on, you should inspect the TPS.

– Disconnected Hoses

Hoses that are disconnected can also cause your vehicle to vibrate. Hoses are the weakest structural components of an air conditioning system, and they’re made of flexible rubber. When the hose is loose or disconnected, it will disrupt the flow of your car’s air conditioning system.

It’s very common for a hose to get disconnected from the engine mount. Sometimes, they may not disconnect completely but will only loosen. Either way, this will not allow proper airflow to your vehicle’s AC system, and you may end up experiencing shakings or vibrations. You might also notice that your car overheats occasionally.

– Dirty Throttle Body

A throttle body’s role is to maintain the airflow to your car’s engine. This component gets dirty quickly, and when it does, your engine won’t get sufficient airflow anymore. As a result, your car vibrates when you turn on the AC unit because it isn’t getting enough air to condense and release into the vehicle. The dirt can also cause your car to rough idle.

– Faulty AC System

While a compressor is a major part of a vehicle’s air conditioning, it is not the only component in an air conditioning system. If your AC system is failing or in need of maintenance/repair, you may find yourself with a shaky car whenever you turn on the air conditioning. Car AC systems are complex, and any malfunction or damage to any of the components can ruin the system’s performance. The damage can cause side effects like ineffective cooling or vibrations.

– Damaged Mass Airflow Sensor

This component, also known as a MAF sensor, is a critical part of a vehicle’s electronic fuel injection system. When this component is bad, one common symptom is that the car will vibrate while running with air conditioning. Another common symptom of a faulty MAF sensor is when the car jerks when idling.

If there is one thing you shouldn’t fail to check when troubleshooting the cause of your car shaking, it’s the MAF.

– Faulty Engine Mounting

A shaky vehicle can sometimes result from a loose engine mount. This component holds your car’s engine and transmission correctly. When car manufacturers produce a vehicle, they bolt the engine and transmission together. Then they use the engine mounts to hold them together, providing a solid foundation with no room for shaking and vibrations.

Turning on your air conditioning while driving puts a load on the engine and strains the mount. Over time, when the mount is exposed to constant strain (perhaps due to overuse of your AC), it can wear out or even break. Worn or broken motor mounts cannot tolerate much load or strain, so there’ll be a lot of buckling or shaking, especially when you put on your air conditioner.

One sign you can use to tell that you have a bad engine mount is when you hear a clicking noise from your car or when your car jerks. If you see these signs, take your vehicle to an auto repair shop so they can fix the motor mount.

How Can You Fix if Your Car Shakes When the AC Is On

To fix a car that shakes when the AC is on, you can check the MAF sensor and clean it if it’s dirty. You can also check your transmission mount, repair or replace a damaged air conditioning compressor and tighten or reconnect hoses that are loose or disconnected.

– Check Your MAF Sensor

As mentioned earlier, this sensor is one of the main causes of a shaky vehicle. Check to see if it is dirty and clean it. You can find the MAF sensor between the air filter and the throttle body.

You can clean a dirty MAF at home, but ensure you turn off the engine and remove your car key from the ignition before you touch it. If the sensor seems bad, seek a professional mechanic for replacement.

– Check Your Throttle Position Sensor

You can reset this component by unhooking the negative cable from your battery for five minutes or more. After you rehook the cable, the sensor should work properly. Another way to reset it is by removing the fuse for your engine control module.

– Clean Your Throttle Body

You will need a cleaner for this (like a brake cleaner). Spray the cleaner inside the air duct and use brushes to clean it thoroughly. Remember to take note of the previously attached hoses (you should label each one before disassembling them), so you can assemble them back properly.

Cleaning this component will make air flow properly to your engine and eliminate the shaking. If you are not good at DIY repairs, you can take your vehicle to a mechanic to get the part cleaned for a few dollars.

– Check Spark Plug

Checking for and replacing faulty spark plugs is the easiest DIY check you can do. If you find this is the problem, simply use a plug spanner to remove the bad plugs and replace them with good ones.

Frequently Asked Questions

– Why Is Your Car Misfiring When You Turn the AC On?

Your car is misfiring when you turn the AC on, most likely due to a faulty air compressor or some malfunction in the air blower. A faulty compressor will always cause this issue. It could also be that the engine is carrying an excessive load and needs to be checked.

– Why Does Your Car Shake When You’re Accelerating?

Your car shakes when you’re accelerating due to damaged or broken engine mounts leading to car vibrations while you are accelerating. However, the issue could sometimes result from imbalanced tires or a bent axle. Other causes include inadequate combustion and a bad TPS, among others.

– Can You Drive Your Car When It Is Shaking?

No, it isn’t safe to drive when your car is shaking. You should try to trace where the problem is coming from. Ignoring the shaking for too long can cause severe complications. If you can’t find what’s wrong with the car, get an expert to help you.

Create a schema markup for all the following FAQs:

– Why Is Your Car Misfiring When You Turn the AC On?

Your car is misfiring when you turn the AC on, most likely due to a faulty air compressor or some malfunction in the air blower. A faulty compressor will always cause this issue. It could also be that the engine is carrying an excessive load and needs to be checked.

– Why Does Your Car Shake When You’re Accelerating?

Your car shakes when you’re accelerating due to damaged or broken engine mounts leading to car vibrations while you are accelerating. However, the issue could sometimes result from imbalanced tires or a bent axle. Other causes include inadequate combustion and a bad TPS, among others.

– Can You Drive Your Car When It Is Shaking?

No, it isn’t safe to drive when your car is shaking. You should try to trace where the problem is coming from. Ignoring the shaking for too long can cause severe complications. If you can’t find what’s wrong with the car, get an expert to help you.

Conclusion

Now you know the various things that can cause shaking in your car when you turn on the AC and how to fix them.

Here’s a summary of the quick fixes you can do in case of emergencies:

• Check for loose hoses and mounts. Tighten the hoses, if any, by yourself, but take the vehicle to a technician if you find a loose mount.
• Replace old or faulty plugs.
• Check the throttle body to see if it is clean. If it’s not, clean it.
• Check for signs and symptoms of damaged fuel injectors (misfiring, rough idling, etc.) and seek a professional to repair or replace them for you.

Shaking vehicles can be a big problem, and sometimes, it is best to seek expert help immediately after you notice it. However, if you love DIY fixing, use the information in this article to trace the cause of your vehicle vibrations and apply the necessary fix.