Hello guys. I have a Civic 1.6 I-dtec with around 136k km on board. I am experimenting this strange sound, sort of whistling. It doesn't happen everytime and i can't figure out the exact conditions. It makes it randomly. In happens in the turbo RPM zone more often when changing gears while decreasing RPMs. Let's say i am in the second gear at 3000 RPM, hit the clutch to change to third. While the RPM goes down it whistles. Other times it makes the same sound while accelerating in the same RPM zone (over 2000 rpm). I asked the Honda dealer's mechanic and he said that is somehow normal, but this only started like 2-3k km before and i don't know what to think. What do you think? Can be the turbo? a hose? The engine didn't lose power, but it sounds raspier on start-up and idle. I maintain it really well, change oil at maximum 8k km and always use Honda or Castrol Honda Oil, never step on it cold, never kickdown under 2000 RPM.