i hear a hissing noise whenever the engine is running. is it normal 'cause of the turbo ?

 

Yes, that is normal turbo noise.

 

Does the 'hiss' change pitch when you rev the engine? I'd describe the turbo as more of a whirring or whine rather than a hiss. If it's just a steady hiss, I'd be thinking fuel pump. (At least that's been my experience.) Not a problem, but a normal sound.

Mike

 

I think the hiss is just the pressure relief/blowoff valve from the turbo.

 

thanks guys for explaining.
It is a high pitch hissing noise appears whenever the engine is running. After cutting off, it's still there for a while. I think it's come from the turbo.
Besides, when I put my rdx in gear from reverse/neutral, there is always a pretty loud clicking sound come from the underbody and it takes a few seconds. Is it the front differential kicked in ?

 

I also hear this clicking from time to time. What is this???

 

Damn I hear it too and only from the front of the car in the mornings. I'm thinking it's just the cold weather affecting something but I'll bring it up when I go in for my next oil change.

 

EXACTLY when i hear it. in the mornings.

 

It gonna click anytime when i put the gear forward from P or R. Is it from the differential, anyone ?and is it normal Sasair ?

 

yep im hearing the same sound too whenever I shift into D or R but I don't hear it every time.

 

well the clicking is most likely the colder differential fluid not lubricating as well when its cold....as for the hissing usually when an engine is idle it shouldnt be hissing, is it possible something is leaking slowly and burning off? The turbo and/or blow off/recycler valve should not hiss when idling.