V6 TDi whining noise - sounds like a supercharger

**JSRed** · 25-05-2017,05:26 PM

Just wondering if anyone knows what the whinging noise I've started experiencing could be, before I take into Audi. Car is a 2017 A6 3.0 TDi V6 biturbo 320 BE.

It started the week, only really notice it above 3000 rpm. It's this quite distinct whining noise like a supercharger that kicks in. I've shifted into neutral when driving and the noise remains if I rev above 3000 rpm, so assume I can rule out it being the transmission.

Thanks in advance

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**Guest 2** · 25-05-2017,05:45 PM

Worry about it in 1,000 miles, the parts in the car are still bedding in so noises and smells are expected.

**JSRed** · 25-05-2017,05:47 PM

Ok thanks. I've only just gone over 3000 miles but it's quite distinct and started this week. No apparent error messages and car is driving fine.

The only thing I would say (and this probably isn't related and started before the hot weather) I've noticed the fan comes on an awful lot when parking up, even after short journeys where it wouldn't get to temperature)

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**Justinos** · 25-05-2017,06:58 PM

Noticed same on mine, and only done 1600 miles. Perhaps noticing now as you are revving more after the run in period.

I had a gearbox replaced on my last one for similarish noises, but that was an Stronic, and was more of a whine/whistle, so I will be listening carefully. When I heard this on the BiTdi, first thought was sounds like a supercharger, so with it on two cars it must be a characteristic. Could it be the exhaust sound enhancer?

**JSRed** · 25-05-2017,07:07 PM

That's useful to know that yours is doing the same. To be honest, I haven't run mine in. Never do on any new cars I've had. Just enough to get the brakes bedded in etc then drive it like I drive usually (which can be quite hard). Never had a problem with an engine, but my last car (Golf R) had a new clutch after the pressure plate failed after 5k... but it appeared the MK7 R had a weak clutch with loads going so I don't blame my driving for that 😂

I've turned the exhaust off completely and it still does it... maybe it's a characteristic. Just funny it's just started doing it now

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**NewAudi** · 25-05-2017,07:59 PM

I did not have any whining noise on my 2014 (313) BiTdi but the fan would kick in very frequently when new and still did on occasion after 3 trouble-free years. On my new S6 the fan comes on after pretty much every drive since the day I got it so same thing.

Possible that the whining is simply the turbos spooling up.....

**JSRed** · 25-05-2017,08:03 PM

Originally Posted by NewAudi

I did not have any whining noise on my 2014 (313) BiTdi but the fan would kick in very frequently when new and still did on occasion after 3 trouble-free years. On my new S6 the fan comes on after pretty much every drive since the day I got it so same thing.

Possible that the whining is simply the turbos spooling up.....

The fan thing is a bit strange. It's very fan happy!

The whining has only just started, and I've not changed my driving style - it's always been revved the same so that's why I noticed the different sound from the same driving. It's definitely sounds like a supercharger (like on the first mini Cooper S, before they replaced the supercharger with a turbocharger).
I can still hear the whoosh of the turbos.

Who knows what is going on...

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**NewAudi** · 25-05-2017,08:38 PM

Originally Posted by JSRed

The fan thing is a bit strange. It's very fan happy!

The whining has only just started, and I've not changed my driving style - it's always been revved the same so that's why I noticed the different sound from the same driving. It's definitely sounds like a supercharger (like on the first mini Cooper S, before they replaced the supercharger with a turbocharger).
I can still hear the whoosh of the turbos.

Who knows what is going on...

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Re the fan, this seems quite normal by the look of things. I have had many other cars (other makes) that did the same when new.

Re the whing, I would just wait and see. I am sure theres nothing wrong with the car.

**ukgroucho** · 26-05-2017,02:11 PM

Of course it might not be the fan - it might be trying to complete a DPF regen... you get a sound of a fan running and lots of hot air coming out from under the front of the car.

You can kinda tell if it's trying to do a regen because it seems to also adjust its gear shift selection - holds lower gears to keep engine temp up. If you have the exhaust in dynamic mode it's noticeable that the car seems noisier (akin to sport mode). It's subtle but once you understand the feel of the car you will start to notice and will be able to tell when a DPF regen is under way - I now routinely take the car for a 15 minute drive in sport mode to get the regen to complete.

**Widwow** · 26-05-2017,02:32 PM

Personally, I think what you are noticing is this - as the turbo's are variable vane, and the turbo's work to support each other, From about 2500rpm, a changeover valve connecting the two turbo's starts to open up together to bring the larger turbo into play. About a thousand or so revs higher, and that valve is completely open as the small turbo becomes redundant and its larger brother provides the engine boost at higher revs. As the car is run in/used more/increased in mileage, the turbo's are now working more efficiently and increasing in performance, sucking and blowing more air.

Very little to worry about I would have thought.

EDIT - could be complete BS - but I found this... words to the effect of here

http://www.caradvice.com.au/213130/a...0-tdi-biturbo/