Hello

What would be your guesses about these two kind of sounds please?
(I would locate them somewhere on the left side of the engine compartment, i.e. driver's side.)

The first one occurs on a cold engine, after 0°C night, and goes away after a minute or two maybe...
My guess would be some kind of a belt?

This second one I noticed tonight after a 15-20 minute ride, hence I believe the engine was warm enough...

 

Take the SC belt off and see how it sounds?
You have a 2008 (I think?) and it should have the upgraded idler/belt and pulley setup?

Have you seen this TSB about belt noise and it's solution? The cut off shows 2007 so may not apply to your year?
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The first one sounds like a belt (maybe I should have separated them both), "chirping" would describe the sound better. (As described in the PDF you linked.)

The other one sounds more like ticking to my ears, that one I want to have looked at this upcoming Thursday.
I was hoping someone could recognize the sound before I get to the service shop.

 

OK, the ticking sound is gone. Maybe it was the sound of the air-pump...? (Just in case, the BagpipingAndy's repair kit is already on its way to my garage.)

 

So apparently that sound is the lifters.
...perfectly described and also explained here:

 

interesting. The idler pulley on my 2004 VDP is not flanged.