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caeci11ius
08-11-2013, 11:53 PM
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
09-11-2013, 12:11 AM
Just a guess...Could be the electric water pump kicking in?

caeci11ius
09-11-2013, 02:17 AM
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
09-11-2013, 02:59 AM
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
09-11-2013, 03:30 AM
Could be the waste gate rattle.

caeci11ius
09-11-2013, 12:00 PM
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/0B6k4AzGl5ehYRUlEYXBudjJOTGM/edit?usp=sharing

harrybne
09-11-2013, 05:26 PM
take it to a dealer and show them the video?

caeci11ius
09-11-2013, 06:24 PM
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
09-11-2013, 06:25 PM
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
09-11-2013, 06:27 PM
Could be the headlight level adjusting motor.

Idle
09-11-2013, 08:13 PM
Could be the headlight level adjusting motor.

Better not be! It's really loud and the vibration is quite strong — but I'll admit I didn't lift the bonnet and look.

On my old Mk 6 the headlight motor could be heard,but only just — besides, it has to be run from the dash (halogen lights — not xenons and anyway they were turned off.)

exzibit
09-11-2013, 09:08 PM
Can't hear it in your video but my 90TSI MK7 had the wastegate rattle at around 3k rpm, and more prevalent in sports mode. Annoying as crap. I got the clip installed*from VW and problem solved. Took them 4 months but eventually got it done.

wai
10-11-2013, 07:02 AM
...besides, it has to be run from the dash (halogen lights — not xenons and anyway they were turned off.)

Not if there's a fault causing it to be run.

caeci11ius
10-11-2013, 09:37 AM
I now think it is the waste gate after all...drove it with the window down last night and it sounds more like that than it did with the window shut. Seems to flutter more rapidly than the other ones I've seen posted so it sounds a little different but definitely more like it once you open the window. I assume that's a a quick and simple repair then (if it's that?)?

Idle
10-11-2013, 10:23 AM
Not if there's a fault causing it to be run.

Checked the light aiming system and it's working correctly — the motors are almost inaudible.

The noise can only have been one or both cooling fans running flat out (I believe there's a pump to cool the turbo on the Mk7 TDI, but any noise from it should be muffled — this was frighteningly LOUD, very obvious and vibrating the front of the car, which those tiny motors just couldn't do.)

When it shut off after about six minutes it ran down rather than just stopping, which again suggests fan or fans (there are two.)

Next time (if there is one — probably will) I'll look further into it — just thought it might help the OP to locate the source of his/her noise.

caeci11ius
10-11-2013, 10:54 AM
Idle - cooling fans in the diesel are normal after shutdown when the diesel particulate filter is being regenerated (it gets very hot...800 degrees I believe). I shouldn't think they should vibrate though, but I wouldn't be surprised that they were quite loud...

Idle
10-11-2013, 01:05 PM
Yes, I'm well aware of that — this is my second turbo TDI and somewhere about my 80th vehicle — but the Mk 6 fans were much quieter, smoother running and didn't wake the neighbourhood.

caeci11ius
10-11-2013, 01:21 PM
...this is my second turbo TDI and somewhere about my 80th vehicle...

My bad, carry on :-)

GeckoZAO
11-11-2013, 11:17 PM
is it the sound at around 0:11 of the video?
i have to pay attention to mine as well!!!

caeci11ius
28-11-2013, 11:28 PM
In case anyone was wondering, it was the waste gate rattle in the end. Fixed in half a day by the dealer fitting the clip. Haven't had any problems with it since.

bru20vt
29-11-2013, 11:06 AM
Can someone show me a picture of where this waste gate rod sits in the engine bay.

exzibit
27-01-2014, 10:04 PM
I've already had the clip installed to fix the wastegate rattle a while ago. Unfortunately, and frustratingly, there seems to be another sound that has surfaced. Its like a low clicking sound when accelerating. Don't have time to bring it in to check but goddamn if this car is a headache.