Good day - There is a whistling/hissing/whirring (don't know the exact term) sound in my 2023 Mitsubishi Montero Sport GLS AT @ 20-40 KPH. Mechanic said it is the turbo but I am wondering why the turbo will sound like that and why it works @ low speed. Turbo should kick in @ 80+ KPH. The sound start @ 20 and sound goes high up to 40KPH but once I reach 40 and up the sound dissappear. The ride is good, no problem with the acceleration, only the sound at low speed during stop and go.

Thanks in advance for your response.