What are the symptoms of a faulty carbon canister purge valve?
2 Answers
Symptoms of a faulty carbon canister purge valve: 1. Increased fuel consumption with noticeable gasoline odor inside the vehicle; 2. Difficulty starting the engine, frequent stalling, often requiring multiple ignition attempts, and easy re-stalling after startup; 3. Abnormal noises during driving, specifically characterized by occasional clicking sounds when not in idle state. Methods to determine if the carbon canister purge valve is damaged: Since the activated carbon canister purge valve operates intermittently, under normal conditions it should exhibit intermittent suction. When the hose on the activated carbon canister purge valve is disconnected, wait for the valve to activate and partially block it with your hand. If you feel continuous suction or no suction reaction at all, this indicates the carbon canister purge valve is damaged.
When my car's purge valve (carbon canister solenoid valve) fails, the most common symptom I notice is extreme difficulty starting the engine, sometimes requiring multiple attempts to ignite. At idle, the engine noticeably shakes or has unstable RPM, making the car feel like it's wobbling while driving. Another major issue is the strong smell of gasoline, noticeable both inside the car and around the rear after parking, especially on hot days. This is mainly because the carbon canister stores fuel vapors, and the solenoid valve controls the entry of these vapors into the engine for combustion; once it fails, vapors leak out and can't be recycled. The check engine light also frequently comes on, and scanning with a diagnostic tool reveals solenoid valve-related trouble codes like P0446. Additionally, the fuel pump nozzle tends to automatically shut off during refueling due to system pressure imbalance. Fuel economy also drops, as I've noticed a significant increase in fuel consumption—vapors are wasted directly instead of being converted into power. So, as a driver with years of experience, I'd recommend getting it checked as soon as possible to avoid worsening the problem.
