Golf R Metallic Ringing Noise

[rosslm]

Ok guys, well I have good news and bad news.

I'm pretty sure I've found the source of the rattle. The bad news - I don't think it's going to be easy to fix, without removing the dump pipe to fix, or by replacing it obviously..

The rattling sound sounds suspiciously like the metal shroud/cage around the downpipe flex joint. Unfortunately this will be pretty difficult to access without removing the downpipe. Likely why VW wont release a 'fix' for it, because its at least 3-4 hours of work just to get the downpipe out!

I made a quick video to explain:





All good bud, happy to help

How about titanium insulation tape around that flex joint, it may muffle that clanging sound is it possible to get access to apply the tape in situ

[Primordial]

Thanks Jon, great detective work. It's looking more and more like a new DP is the way to go  (and therefore an intake and tune as well  )

Well, there's a couple of other great reasons as well! Fixing the rattle was just a bonus

How about titanium insulation tape around that flex joint, it may muffle that clanging sound is it possible to get access to apply the tape in situ

Potentially, yeah. I'm trying to remember back when I had the car up on the hoist. I do remember seeing the flex joint in-situ, but I can't remember if it was accessible or not. You may be able to get to it without taking it out, and yeah, the titanium wrap would definitely sort the issue out!

You can definitely get enough clearance with a standard car jack to take a look at least. You will probably have to remove the plastic undertray to be able to see up there though. It's pretty easy, there's 7 torx screws to detatch the undertray.

[TFAD]

Hi Jon

Thanks for the video. To me the sound when you tapped the heat shroud is much closer to what I'm hearing - it has that sort of resonance where the sound lingers slightly rather than the scratchiness of the heat shroud.

Is there anything around the heat shroud it that might come into contact with it?

Tom (TFAD)

[Primordial]

Hi Jon

Thanks for the video. To me the sound when you tapped the heat shroud is much closer to what I'm hearing - it has that sort of resonance where the sound lingers slightly rather than the scratchiness of the heat shroud.

Is there anything around the heat shroud it that might come into contact with it?

Tom (TFAD)

Hey Tom, from memory no there's nothing that comes close to the heat shroud for it to vibrate against.

I would be extremely surprised if it was the upper heat shroud causing the noise (unless you're hearing a different noise?). It's almost certainly the mesh cage vibrating, in person it sounds identical to the rattle I was hearing. What you have to remember is that the mesh cage is vibrating at 40hz roughly (2500rpm/60 secs). It's going to sound like a 'lingering sound' as the revs increase and the cage moves out of its resonant frequency.

[shakespeare]

I too have the noise and with almost 3,000kms on the Wolf Wagon it's still there!

Maybe stage 2 is the best solution...

[andrew7]

^ I've done 5k km and its as bad as ever (irrespective if cold/heat) so unlikely to change.

I'm currently considering a package to "remedy" the situation: Intercooler, CTS Down Pipe and a JB1 tune (Stage2). (as a side Primordial, can you give us a review of how you are finding your Stage 2 set-up?).

its a fair sized $ investment but has the advantage of a tidy performance gain, richer/deeper sound and no more rattle! Its either do that, spend the coin or sell the Wolfie as its currently that bad that I've almost go no choice

[Primordial]

I'm currently considering a package to "remedy" the situation: Intercooler, CTS Down Pipe and a JB1 tune (Stage2). (as a side Primordial, can you give us a review of how you are finding your Stage 2 set-up?).

Shall do. Getting some stuff done on Saturday, and then turning the JB1 right up to see how she goes. I'll reserve a full review until then. For now though, a short review - With Stage 2+, and running JB1 on Map1 5.0 boost - this thing is a BEAST!!

[TFAD]

I've been reading some forums on the Audi S3 which has a similar issue apparently.

One of the comments linked to a video of a guy explaining how a turbo operates. Every time he opens the wastegate it makes a metallic noise and a lot of people on the forum think this is the issue with the wastegate fluttering as gas exits.

https://www.youtube.com/watch?v=AUimU2C2H8U

If it is this then it echoes what my dealer said about it relating to the turbo and being 'normal' (i.e. too expensive to fix)

[Primordial]

I've been reading some forums on the Audi S3 which has a similar issue apparently.

One of the comments linked to a video of a guy explaining how a turbo operates. Every time he opens the wastegate it makes a metallic noise and a lot of people on the forum think this is the issue with the wastegate fluttering as gas exits.

https://www.youtube.com/watch?v=AUimU2C2H8U

If it is this then it echoes what my dealer said about it relating to the turbo and being 'normal' (i.e. too expensive to fix)

That whole wastegate fluttering story sounds like some BS a dealer service advisor has made up to get a customer off his back. The wastegate WAS the issue on MK6's - it was the wastegate actuator rod (not the wastegate itself) vibrating causing the noise.

On the MK7 the issue definitely has to do with the downpipe, that's a fact. Changing the downpipe does fix the issue. I'm 90% certain it's the cage around the flex joint vibrating on the standard downpipe.

Does anyone want to get up under theirs and see if they can get to the flex joint? If so, it might be an easy fix by just wrapping the flex joint with some exhaust wrap.

[andrew7]

Agree Jon 100%, it's a total snow job by VAG. I'll see if I can get my car to a good independent before Christmas and check this if this works. If not hello CTS DP, CTS intake and Stage 2 😊