Mystery noise from under the hood

[Zaskar]

My T5 crewvan has started making a strange buzzing or humming noise. Its getting more frequent, however i cant find a commonality. My best guess guess is a noisy power steering fluid pump (if there is such a thing).

It happens with or without air con, so its not that fan. It only lasts 0.5-1.0 seconds so i cant record it.

The van's still under warranty, but I'm pretty sure 'funny noises' aren't covered.

Does anyone have any suggestions?

[IN2VWS]

When does it happen? When you are turning? Driving at speed in a straight line?

[Zaskar]

When does it happen? When you are turning? Driving at speed in a straight line?

I haven't been able to discern a commonality. Its seems to happen at random times, although more frequently lately.

[yt5]

does it sound like a cow mooooooo! if so it counld be the n57 valve

[Zaskar]

yeah it is a little cow like
Ohhh of course the N57 valve... (whats that)

does it sound like a cow mooooooo! if so it counld be the n57 valve

[REVHE4D]

I started to get this intermittent Moo/humming/vibration sound myself as of the last service, soon as I take my foot off the gas it goes away. And I only hear it every other day on and off. I did have a problem 2 years ago with my new n57 valve that was replaced under warranty due to my vw humming when the engine was turned off, and losing boost at low revs. Do you guys think it's the same valve?
If so my vw is just out of warranty what are our options?

Sent from my SM-N9005 using Tapatalk

[greymad]

So what, please, is the "n57 valve" - or is it a state secret...

[brad]

boost control valve was the first hit when I googled it

[Robear]

Mystery noise from under the hood

Now this is a weird one. It's something that happens intermittently so difficult to show the service guys on a test ride. Sometimes it can happen 3 or 4 times in 10 minutes, then sometimes not for 20 minutes at all...I have attached a Youtube link here from my dash cam, but for those who cant get there, its a mechanical noise that sounds like an electric aerial winding down, but only for a second, sometimes longer.

Can someone shed some light on what it could be? Its a Multivan Edition 25, I have turned off the heater, the radio, but have no idea what it may be, any suggestions would be lifesaving as its driving me insane...

http://youtu.be/PXl99edCTB8

Thanks in advance

[REVHE4D]

That is the same noise my t5 is making since my last service, and my warranty has just run out. This is starting to sound like a common problem. There is a thread here about intermittent buzzing regarding similar users.
Does anyone know if i can get this covered under warranty even though it has just run out?
This is sad to see so many of us with this issue.
As others have suggested it most likely is the boost release valve. It seems to be faulty.

Sent from my SM-N9005 using Tapatalk

[greymad]

boost control valve was the first hit when I googled it

OK - thanks for that ... my buzzing noise generally seems to occur when I back off the throttle, even after quite gentle acceleration.
It's driving me nuts.

[Robear]

OK - thanks for that ... my buzzing noise generally seems to occur when I back off the throttle, even after quite gentle acceleration.
It's driving me nuts.

does it sound like this? I captured it with my dashcam http://youtu.be/PXl99edCTB8

If so we are in the same boat I posted about it yesterday...

[lordsword]

does it sound like this? I captured it with my dashcam http://youtu.be/PXl99edCTB8

If so we are in the same boat I posted about it yesterday...

That's definitely the noise I have noticed.
I've only ever had it happen on 2 occasions and mine were both after I'd been idling in a parking lot waiting for a park on and off the throttle/clutch for a period of about 5 mins. Then when I switched off the car to get out, I would hear that exact noise. More like the second one in your video where it seems to fade out (a lot more like a cow moo-ing)
No idea what it is, but if it was happening as often as in your video then I would be real freaked out!! It's quite a strange noise.....

[SnowMotion]

I think I can help with this noise. I had a similar problem with my T5.2 and asked the dealer I purchased it from to diagnose the fault. During the 3 hours they had the van they could not find a fault.
So took my van to my local dealer (Bill Buckle Brookvale. very helpful). Took a tech for a 20 second drive and he diagnosed the fault.
Turns out it is from a faulty Overboost valve.
Apparently it is a known problem and there is a prescribed fix for the problem.
Sounds like a bee stuck under your bonnet.
If you play around with your throttle you will notice it happens when you slightly lift your foot on the throttle.

[SnowMotion]

As I posted in the other thread, sounds like a faulty Overboost valve.

VW in Brookvale knew of the problem and said there was a prescribed repair for the fault.