What causes the abnormal noise when stepping on the accelerator in a Sylphy?
2 Answers
The reasons for abnormal noise when stepping on the accelerator in a Sylphy may be: This phenomenon is likely caused by the sound from the valves, or it could be due to insufficient engine oil leading to lack of lubrication in the valves. During cold starts, the engine noise is generally slightly louder than when the engine is warm. The reasons for abnormal noise when stepping on the brake in an automatic transmission vehicle are as follows: 1. Normal activation of ABS: The working process of ABS is actually a cycle of locking and releasing, keeping the vehicle in a state of critical lock rolling. When you step on the brake hard and trigger the ABS, it will produce a clunking sound, which is normal. In this case, simply press the brake pedal firmly to the bottom. 2. The gear makes a "clunk" sound when stepping on the brake in an automatic transmission vehicle: If you hear a "clunk" sound between the transmission and the gear lever when stepping on the brake pedal, the main reason for this noise may be the electronic linkage between the brake system and the automatic transmission. When you step on the brake, the transmission solenoid valve opens and produces a "clunk" sound. At this time, you need to press the gear lock button to shift gears, which serves as a safety reminder.
A while ago, my friend had the same issue with his Sylphy. After some troubleshooting, we figured it was likely the belt system causing trouble. If you hear a high-pitched squealing or chirping sound when you press the accelerator hard, it’s probably due to an aging alternator belt or a faulty tensioner pulley. If it’s a metallic tapping sound, you should check if the engine mount rubber has cracked—when that fails, engine vibrations become much more noticeable. Another often-overlooked culprit is the charcoal canister purge valve, which makes a clicking noise when it draws in fuel vapors, becoming more pronounced under heavy throttle. Honestly, rubber components in a car should be replaced every five or six years, especially high-vibration parts like belts and mount rubbers. My advice is to find a quiet spot, roll down the windows, and slowly press the accelerator while someone outside helps pinpoint the noise source—this way, repairs can be more targeted.
