What Causes Engine Vibration When the AC is On in a Honda CR-V?
3 Answers
There are two main reasons why the Honda CR-V experiences idle vibration when the AC is turned on: one is a load sensor issue, and the other is engine mount damage. It is recommended that the owner promptly seek repairs to avoid affecting vehicle usage. More details are as follows: 1. During normal engine operation, vibrations occur, including after starting the compressor, but they are partially filtered out by the engine mounts, making them less noticeable. Engine mounts are located between the body and the engine and are part of the vehicle's engine vibration isolation system. 2. If the engine mounts collapse or become damaged, the engine's balance is disrupted, and turning on the compressor may reach a resonance frequency, intensifying the vibrations. 3. Idle refers to the state where the engine operates at its lowest speed without additional loads. Turning on the AC increases the load, and the engine load sensor detects this increase, transmitting the signal to the engine control unit (ECU), which then commands an increase in engine speed to accommodate the additional load. The engine automatically increases the throttle opening to allow more air intake, thereby boosting power output. 4. If the throttle valve is not maintained for a long time, carbon deposits can easily accumulate, obstructing engine air intake. This can result in the engine struggling or barely managing to drive the compressor, leading to idle vibration.
My Honda CRV shakes when the AC is on, especially noticeable when idling at traffic lights. I asked a few friends who drive the same model, and they all said it's caused by the AC compressor. The engine originally runs smoothly, but when the compressor kicks in, it has to work extra hard to power it, making the engine struggle a bit. If the engine mount rubber parts have aged and the damping effect weakens, the vibrations directly transfer to the car, making it shake even more. Other possible causes include worn spark plugs misfiring or a loose belt slipping. I’ve also encountered issues with the fan motor adding to the trouble, so I recommend regular maintenance checks to prevent small problems from becoming big ones. Delaying repairs not only makes driving uncomfortable but may also accelerate component wear and increase fuel consumption—safety first.
As a Honda CR-V owner, I've seen this issue of car shaking with AC on many times. When the compressor kicks in, the engine load increases, making it prone to shaking at idle. The most common cause is often a failed right front engine mount rubber—once the rubber part ages, the vibration damping is gone. Loose belts or a slipping compressor clutch can also contribute. Ignition system problems, such as faulty spark plugs, can similarly cause misfires and shaking. My advice is to first use an OBD scanner to check for trouble codes and pinpoint the cause. Don't slack on regular maintenance—changing the air filter and cleaning the throttle body can prevent issues before they arise. Addressing problems promptly ensures smoother driving and much greater peace of mind.
