Why does the new Qashqai make a whistling sound when accelerating and decelerating?
2 Answers
The whistling sound in the new Qashqai occurs because when the throttle is released, the pressure relief valve discharges the already compressed air that was supposed to enter the cylinders, resulting in a whistling-like exhaust sound. Introduction to Pressure Relief Valves: When the pressure inside a device or pipeline exceeds the set pressure of the relief valve, it automatically opens to release pressure, ensuring that the medium pressure within the device or pipeline remains below the set level, thereby protecting the equipment and pipeline and preventing accidents. Precautions for Pressure Relief Valves: They should automatically open when the safe pressure limit is reached to reduce pressure and ensure safety. Pressure relief valves can be installed either horizontally or vertically, but the direction of the valve's water inlet and outlet must be correctly aligned during installation. Generally, one pressure relief valve is sufficient for a single fire water supply system. If the drainage outlet of the relief valve is far away (greater than 20m), the diameter of the drainage pipe should be one size larger than the relief valve's specification to prevent backpressure caused by poor drainage and to maintain stable pressure in the pipeline network before the valve. If the relief valve malfunctions during operation, first check whether the pipeline is unobstructed.
I've been driving for over a decade and encountered the whistling sound when accelerating or decelerating in the new Qashqai, which is quite common and usually related to the turbocharging system. The new Qashqai comes with a turbocharged engine. When you quickly press the accelerator, the turbo blades spin faster, and air passing through narrow pipes creates high-speed airflow noise, sounding like a whistle. When you release the accelerator to decelerate, the sudden change in airflow produces similar noise. It could also be related to loose intake pipes or aging seals causing air leaks, leading to abnormal airflow sounds. I suggest you pop the hood to listen for the source and regularly visit a service center to check pipe tightness and seal conditions. Ignoring it early on might turn a minor issue into an air leak fault, affecting engine performance. Regular maintenance can save you a lot of trouble.
