Only few hundred kilometers after changing the head gasket which set me back quite a few €€€ I noticed some weird (turbo?) whine on spool down, like a sick cat moaning.

https://youtu.be/8Fx5EI4CU0I

It can be heard distinctively on two occasions in the vid.

Has anyone had similar issues or can recognize what is this sound?

One thing to note, when changing the head gasket the turbo oil feed pipe was changed. Could any of this be connected?

Can't really tell, sorry.

Possibly a boost leak if a pipe isn't on 100%

As for the oil feed pipe, it depends if it was primed up before starting, both just guesses though.

Sometimes videos can be a bit deceiving with how they capture and present different sounds, but like hutchy said, does sound like you could have a boost leak.

I think I can hear the noise in the background you are perhaps referring to. Not sure I'd be overly worried though if I'm honest.

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And just to add, it sounds more whooshy than whiney in my opinion and from the experience I've had with my car, this is probably air escaping the boost circuit somewhere rather than the turbo nailing it's coffin shut lol.

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A bit of an update: we've even changed the wastegate valve and the whine is still there, unchanged. Also had many confirmations from other mechanics it's not the turbo (nevertheless I visited a turbo specialist which immediately quoted me a "friendly" price, just to bring the turbo to him, as it's "definitely the turbo" ).

 

Suspicion 1: Whine is much louder when cold. Cold turbo noise reminds me that there is a valve operating the turbo when the engine is cold - I remember someone mentioning that the vRS has this sound until the engine warms up. I suspect it could be that as the sound goes away almost completely after only few hundred meters. I hope I'm making sense here as it's hard to put a finger on what I mean

 

Suspicion 2: Other thing to note is the whine is present only in 1500-1700 rpm range, making it maybe not even connected to the turbo. My mechanic inspected everything with a stethoscope and it could be "some" bearing on the belt side of the engine (I do have AC bearing noise for years now, but only when AC is on, the whine is present regardless of AC on/off). 

 

Any other opinions? Currently I'm driving as usual with tracking if the whine gets worse (I'd even say it got better as I cannot hear it anymore during driving, except when cold).

Easiest thing to do is take the aluminium pipe off from the air box to the turbo and have a look wlat the compressor. Should take an hour Max to do. Will have to unbolt the egr valve. If you can't get your head up there to see use a camera phone.

I have a whine when cold under 2000rpm and on full throttle. My compressor is goosed. However yours could be something else.

Edited 26 May, 201511 yr by stevobeavo

I can hear what your referring to I think but not sure I'd be worried mate. Do you know how many miles that turbo has done? It just sounds turbo diesely to me and I'm not sure my car sounds any different to be fair.

 

there it is after a few days of sitting, cold morning. It is a distinctive whine, really disappears after a minute, when engine is up to temp, the sound is indiscernible. 

 

Since I've put a few km's since first post, I'm not overly worried as everyone mentions, now I'm just curios what makes this sound?

I'd say that could be turbo still. Mine sounded whiny for a few minutes, then went away and only came back high in the revs on full throttle. My compressor wheel was damaged.

For piece of mind I'd remove the egr valve undo the two bolts that hold the aluminium pipe from the airbox to the turbo and info the clip at the turbo end and stuck your phone up there to check the compressor. Doesn't take that long to do.