With the A/C placing extra load on the engine when running, it causes more vibrations than normal. This would be unnoticeable with functional engine mounts, but faulty ones transfer more vibrations and cause the car to shake.
Faulty AC Compressor: A malfunctioning AC compressor can cause the engine to work harder than normal, leading to vibrations or shuddering. Worn Engine Mounts: If the engine mounts are worn or damaged, the extra load from the AC can cause the engine to move more than usual, resulting in vibrations.
You may not realize that a vehicle's air conditioning system can actually consume up to 10% of the engine's power, making proper engine cooling essential for optimal AC performance.
That would be the AC compressor cycling. When the AC compressor is running, it will also run the radiator fan. As the compressor engages, it puts a load on the engine, which is probably the cause of the shake. It also seems the compressor is working harder than usual - the shake shouldn't be noticeable.
If the AC is turned on while the engine is idling; then you get a constant “shudder” or shake; you may have a vacuum leak, the idle speed may be too low, the AC idle speed compensator may not be working or maladjusted, the high side pressure may be high due to overcharge, the condenser air flow may be blocked, or the ...
Also, your ride slows down because your AC causes your RPM to drop, which hurts your acceleration (you want higher revs when you attempt to speed up). You can even test this one out yourself if you have a manual transmission or a manual mode in your specific model.
Load on Compressor
Vehicle air conditioners put an extra burden on the engine. The extra load makes the engine work harder, which in turn consumes more fuel. Not only does it enhance fuel consumption, but the overall performance is then decreased.
If the car shakes when AC is on or shakes more, it's due to the load the air conditioner compressor puts on the engine. This makes issues with idle air control more noticeable, since the engine needs more air to keep running.
A rough idle when the AC is on can stem from issues like a leaky intake manifold gasket, a faulty idle air control (IAC) valve, or an EGR valve that's stuck open.
Motor mounts: It's the job of the motor and transmission mounts to dampen vibration. When they break, you'll feel excessive vibration, especially at idle. You can diagnose this yourself by putting your car in neutral. If the shaking lessens, you very well could have broken mounts.
One of the most common reasons for an AC system rattle is a problem with the belt tensioner. This component is located at the front of your engine and is responsible for keeping the serpentine belt, which drives the air conditioner pulley, tight and functioning properly.
Idling your car with the AC on puts extra stress on your engine and cooling system. The AC compressor draws power from the engine, which reduces its performance and increases its temperature. Additionally, the ambient temperature and the efficiency of your car's cooling system also affect idling time.
Engine. Shaking may originate from the engine for several reasons. There are multiple parts on the engine that can cause vibrations if they're not working as they should. The problem may be as simple as cleaning out the engine's air filter or a more major problem like a failing radiator.
A dirty or faulty IAC valve might not adjust the idle speed properly to compensate for the added load of the AC compressor. This can cause the RPMs to dip and fluctuate. A dirty throttle body can also lead to rough idle and difficulty adjusting idle speed.
Crucial aspects of your car's A/C compressor, like the pulleys and belts, are powered by the engine. When they break or slacken because of a faulty A/C compressor, your engine will work overtime in an attempt to power them. This can cause your engine to wear out more quickly.
One of the most common reasons is a failed clutch. The clutch is responsible for engaging and disengaging the compressor as needed. If the clutch fails, the compressor can stay engaged even when it's not needed, causing a constant power drain. Another reason for a power drain is a leak in the AC system.
So yes, running your air conditioner during hot weather will cause the engine to run hotter. This should not be a problem under normal conditions. However, if the AC cycles on and off continuously, it could mean the refrigerant levels are too low or there is something else wrong.
What are some symptoms of a failing AC compressor? Loud noises, hot air, airflow issues, uneven cooling, and electrical problems are all things you might run into when an AC compressor is on its last leg.
The alternator also powers the rest of your electrical systems, such as lighting or air conditioning, while your engine is running.
On average, an AC compressor replacement will cost $800 to $1200 or more, depending on the make and model of your car. Because it's a cornerstone component of your air conditioning, your AC won't function if the compressor is broken.
Warm Air from the Vents
If the compressor is fine, it will push cold air into the cabin of your vehicle. If you begin to notice warm or even hot air coming out of the vents, this is a clear indication that the compressor is not functioning properly.
The Answer Is Seldom A Simple One
It entails removing and disposing of any remaining refrigerant, disconnecting and removing the old compressor, installing the new one with proper fittings, and recharging with refrigerant. Add it all up and it typically takes four to six hours.