Quiet electro-mechanical noise from front right around 3000rpm

[caeci11ius]

So I've now had my 90TSI comfortline with driver assist for a couple of days. Driving it home the first day, I noticed this quiet noise coming from the front right...sounds a bit like a small pump or something of that nature. I then didn't hear it for a few days, but tonight I drove the car a little more vigorously (I've been babying it in the meantime) and heard it again. Seems to kick in somewhere between about 2.5 and 3.5k RPM but not all the time. Any ideas what it might be and if it's normal? It's not exactly an unpleasant noise (not loud or grinding or anything like that) but it's not something I was really expecting to hear either...

[vk6tnc]

Just a guess...Could be the electric water pump kicking in?

[caeci11ius]

Any reason you'd expect to hear that only when driving moderately (as opposed to very gently and trying to get awesome fuel economy?)? I'd have thought pumps for coolant would be running constantly (and be quiet enough that you couldn't hear them in the cabin while driving)...

[vk6tnc]

Any reason you'd expect to hear that only when driving moderately (as opposed to very gently and trying to get awesome fuel economy?)? I'd have thought pumps for coolant would be running constantly...

The following is taken from VW press releases published on another forum:

The new fully-electronic coolant control system of the TSI enables significantly more efficient thermal management with a shorter warm-up phase; this reduces friction losses, which efficiently improves fuel economy. A new type of rotary vane module was developed for intelligent thermal management control. This makes it possible to fully block coolant entry into the engine or adjust to a minimal volumetric flow in the engine warm-up phase. In the hot operating state, the coolant temperature can be adjusted quickly and fully variably to various temperatures as a function of engine load and external constraints.

[Brew69]

Could be the waste gate rattle.

[caeci11ius]

Video where you can hear the noise. You hear it starting at 1/4 through to about half through, then some more in the last quarter...

Link: https://drive.google.com/file/d/0B6k...it?usp=sharing

[harrybne]

take it to a dealer and show them the video?

[caeci11ius]

Yep, popped into my dealer this arvo. Going back early in the week when the technicians are there. Just hoping to get some ideas of what it might be in the meantime...

[Idle]

Probably cooling fan — took my new TDI110 Highline on the freeway for the first time this afternoon.
Four adults on board, didn't go far (Chandler Highway to Burke Rd and back) with a 2K suburban street run at the end — which ought to have sufficiently cooled the turbo.
When switched off in the garage a fan at front right ran for about 6 minutes — sounded like a buzz-saw and obviously isn't properly balanced, as it vibrated the bonnet and front guards to the extent that I actually checked that the engine was turned off (it was.) It sounded louder than an idling diesel and had at least as much vibration!

[wai]

Could be the headlight level adjusting motor.