If your vehicle is shaking when the auto A/C is turned on, this is not normal and should be investigated. There are several reasons why this phenomenon occurs, and getting to the bottom of it will resolve the issue before it worsens. First, it is essential to understand the critical engine components and how they function with the A/C system.

THE ROLE OF THE COMPRESSOR

The compressor is best thought of as a miniature engine, which puts a great deal of stress on the main engine. As such, whenever the vehicle is turned on, several things are triggered, like the control motor air, so the compressor, although idle, can be elevated through the compensation of additional drag. However, if you notice the car shaking, it means that this process could have become disrupted and therefore inaccurate.

Excessive drag often results from vibrating while idle and is a symptom of engine stalling. In a vehicle that uses power steering, too much drag while the A/C is running could lead to more engine stalling and more significant shaking, and the issue might also be caused by motor mounts that are broken.

ELEVATED PRESSURE

The A/C compressor creates significant engine strain, and should this pressure reach a level higher than 400 PSI; the result could be vehicular vibrations. Should the pressure continue rising, multiple engine components will wear out prematurely. Elevated pressure might also be the result of the cooling fan or blockage within the air conditioning. Unless you’re familiar with your A/C and how to perform maintenance on it, it is best to take it to a technician.

WORN OUT TRANSMISSION MOUNT OR ENGINE

The car mounts undergo a lot of strain whenever the air conditioning is activated. These mounts are important since they hold the transmission in place (along with the engine), designed to maintain the correct suspension angle. The mounts are also responsible for organizing hoses and wiring, keeping them away from noise or vibrations in the environment. Therefore, any problem with the mounts will cause vibrations and shaking. If the mount breaks completely, the shaking may be accompanied by noise, particularly if the A/C compressor kit produces more engine pressure. Therefore, if you notice the vehicle shaking, one of the first things you should inspect are the mounts.

Vehicular vibrations or shaking is annoying to drivers, since most of them realize that it signifies some problem with the vehicle that money, time and effort will require to resolve. Many drivers will make the mistake of thinking the issue will resolve itself, or they can put off until a more convenient time.

DEFECTIVE FUEL INJECTOR

The fuel injector is a vital part of an engine in a vehicle. The fuel injector’s job is to spray fuel into a car’s engine using electronically controlled valves, which can open and close many times a second. The engine needs to fuel-run effectively and also when you turn AC on.

If your car’s fuel injectors can’t function effectively, it strains the engine, and your car will start shaking when AC is on. Even a faulty fuel injector can make your car rough idles when AC is on. Every time you go to the service centre to maintain your car, you should check the fuel injector by a professional.

BAD SPARK PLUGS

The spark plug produces power to your engine by creating an explosion and air/fuel mixture. Damaged or old spark plugs could be the reason why your car engine vibrates when AC is on.

FAULTY THROTTLE POSITION SENSOR

A Throttle position sensor (TPS) job is to monitor the air intake of an engine. The throttle position sensor monitors how far the throttle blade (or valve) can be open, which is determined by how far down the accelerator pedal has been pushed.

The car’s throttle position sensor cannot control the RPM (Revolutions per minute). That’s why if your car has a bad throttle position sensor and you turn on the air conditioner with that issue, then your RPMs do not remain constant for the bad TPS.

So, in this situation, cars can vibrate when idle and AC is on with unstable RPMs if you notice this issue in your car. You should fix or replace the TPS sensor to get rid of car shakes when AC is on the issue.

MASS AIR FLOW SENSOR

When you go to an auto repair shop to fix why your car vibrates when you switch on the AC, the mechanic always checks your car’s air flow sensor because a mass air flow sensor can be another cause why your car shakes when AC is on.

The car engine and car air conditioning compressor produce high pressure on the air flow sensor to blow the cold air. That’s why the air flow sensor can get massy normally. Also, if your car shakes when AC is on high, you should check the car’s air flow sensor properly.

HOSES ARE LOOSE OR DISCONNECTED

Those of you don’t know what houses are in your car. The hoses are the cooling system’s (Air conditioner) weakest structural component, and hoses are made of flexible rubber. For many reasons, your car’s hoses can be loose or disconnected from the engine mount. When hoses are disconnected from the mount, the car shudders when AC is on.

Whenever you inspect hoses that are loose or disconnected, you should tighten the loose hoses. If you see hoses disconnected, connect back to the mount and fix your BMW shakes when AC is on the issue.

FINAL THOUGHTS

Everybody knows that it will cost you high money and a huge amount of time when it comes to the issue in a vehicle. That’s why first detecting what causes car shakes when AC is on is always a great idea.

After discovering why your car vibrates when AC is on, you shouldn’t wait to see if this issue will go away automatically. You have to try to fix the car shaking issue by yourself, and if you don’t have the proper experience, you need to go to a workshop to fix it.

Proper and regular maintenance of your car is always important. Take your car to a professional if your car shakes when AC is on, don’t wait too long because it won’t fix the issues.