Why does the carbon canister solenoid valve keep inhaling at idle?
3 Answers
Carbon canister solenoid valve does not work at idle. If it keeps working now, it is recommended to check whether the solenoid valve control circuit is in the on state and whether the solenoid valve is interfered with, resulting in frequent operation. The following is a related introduction about car idling: 1. The role of car idling: Idling is a working condition of the car, which means that the engine is running in neutral. The speed of the engine at idle is called the idle speed. The idle speed can be adjusted by adjusting the size of the throttle and so on. Idling means the engine "outputs power but does no work". When the engine is running, if the accelerator pedal is completely released, the engine is in an idle state. 2. Reasons for unstable idle speed: Direct reasons refer to mechanical parts being dirty, worn, or installed incorrectly, resulting in changes in cylinder power, which in turn causes an imbalance in the power of each cylinder, leading to unstable engine idle speed; Indirect reasons refer to the abnormal operation of the engine electronic control system, resulting in poor combustion of the mixture, making it difficult to balance the power of each cylinder, causing unstable engine idle speed.
I remember last time when fixing my friend's Corolla, the charcoal canister valve kept sucking air at idle, sounding like wind whistling through a gap. Most likely the solenoid valve was stuck, unable to open or close properly, probably due to accumulated dirt or oil residue making it stubborn. From my experience, this component should only activate during startup or acceleration - it shouldn't be this noisy at idle. Otherwise, the engine's air intake gets disrupted, causing unstable idle and increased fuel consumption. Need to check it immediately - use a multimeter to measure the control signal or relay voltage, don't wait until trouble codes appear or it starts smelling bad. Regular maintenance with valve cleaning to prevent dust buildup can save you from expensive canister replacement later.
My old van has been running for ten years, and the carbon canister valve makes a loud sucking noise at idle. At first, I thought the fan was broken, but upon closer inspection, I found the solenoid valve had failed. It might be stuck in the 'on' position due to rust or a short circuit, sucking endlessly when it should rest at idle. This causes the air-fuel mixture to lean out, resulting in weak acceleration and shaking. I took it apart myself, cleaned the valve core, and replaced the filter—done in ten minutes. I recommend everyone pay attention to strange idle sounds and not ignore them. Small issues left unattended can damage the engine or pollute the air, and replacing the valve at a repair shop isn't expensive.
