Loud "wooo" sound when accelerating

[selp]

I know its strange, but for whatever reason, it feels that it has been getting louder and louder recently. I have done numerous launches and runs, car seems to behave fine and no problems observed other than the loud noise.
It seems to be throttle dependent to a certain extent, and its much louder when the car is cold. At the beginning I thought it was the soundktor but I believe its not ( I still haven't disabled/disconnected this ).
Any help would be greatly appreciated.

Mods:
Neuspeed discharge pipe with muffler delete
HG Intercooler
Catless Downpipe
Injen Intake
Stage 2 ECU/Stage 1 DSG Eurodyne
Dogbone

Regards

[Matt C]

https://youtu.be/zUXow3d3-b0

It is definitely because of this.

[a4000]

lol

[Foagy]

How many miles on the car? To me it sounds a bit like shaft play in the turbo, my 335i had the exact same noise on both turbos and was consuming quite a bit of oil (easily found in the post intercooler charge pipe)

[tsunamis4]

https://youtu.be/zUXow3d3-b0

It is definitely because of this.

C'mon man it's just fer decorations!

[HurrayFive]

How many miles on the car? To me it sounds a bit like shaft play in the turbo, my 335i had the exact same noise on both turbos and was consuming quite a bit of oil (easily found in the post intercooler charge pipe)

This is accurate. It's hard to tell from the video for sure but certainly sounds like the cries of a dying turbo. My original SS Turbalt started making a very similar noise around 5K miles when it was bone stock, was always worse cold at part throttle, took a couple of dealer trips over a week or so for them to finally verify it was a defective turbo from the factory. Shaft play to the point it was actually causing damage to the edges of the compressor wheel. Car still made normal boost and power, and above part throttle it was harder to hear over the rest of the engine.

Our turbos are prone to the turbine shaft shearing and eventually catastrophically failing, my tuning shop has seen it happen on multiple MK7 GTI's, A3's and a single Golf R. If it is something in the center cartridge that's about to go, you wouldn't get much more notice than this until it finally does. The compressor housing is easy to reach on these cars, you can pop off the inlet pipe and scope out the housing and wheel, as well as mentioned above, check for any excessive oil inside the IC piping, neither of those will always indicate trouble though. That noise has been burned into my head from when I dealt with it, and this just sounds similar, I would definitely have your local shop check it out or flash back to stock and make a dealer visit. If the turbo grenade's you've always got the possibility of the engine ingesting pieces and it's suddenly a much more expensive repair. Good luck!

[selp]

Thanks for those with useful information regarding this. I guess its time to put it back to stock and take it in to the dealership.
The noise definitely sounds like its coming from the inside of the car. But I am guessing it could be loud enough that it filters its way inside.

Does the turbo upgrade, or replacement that Audi does, has there been issues observed with the new turbos? or if I get my turbo replaced, I should still expect this issue happening again?

[HurrayFive]

Any aftermarket audio stuff? Improperly grounded amps can strain the alternator and cause an audible whine through the speakers as the revs climb, it sounds similar to your video but not quite the same. I also know next to nothing about the way the soundaktor works, so it's possible that's all it is? Hearing that video instantly brought me back to that noise when my turbo was replaced tho, probably worth a visit to be on the safe side!

[INYAUDI]

This has been my only scare on my A3, mine is supercharger-ish and only in 1st and 2nd at low rpm in manual mode.


Sent from my iPhone using Tapatalk

[WAF]

I've had a whine like that when i first installed my FMIC did you check all clamps?
Is it rpm dependant or does boost affect it? @selp

[selp]

Any aftermarket audio stuff? Improperly grounded amps can strain the alternator and cause an audible whine through the speakers as the revs climb, it sounds similar to your video but not quite the same. I also know next to nothing about the way the soundaktor works, so it's possible that's all it is? Hearing that video instantly brought me back to that noise when my turbo was replaced tho, probably worth a visit to be on the safe side!

That was my thought.. it sounds exactly like a ground signal being picked up in sync with the speakers.. it sounds like it comes from there, but when i get close, the sound is hard to track.

There are no aftermarket stereo anything.. other than the Video in motion mod. It has the B&O audio system from audi.

The car has 13000 miles on it. I use Purol oil, and theres about 1000 miles on this oil change.

[selp]

I've had a whine like that when i first installed my FMIC did you check all clamps?
Is it rpm dependant or does boost affect it? @selp

The intercooler has been installed for a while now. It doesn't seem to be boost dependent, more throttle than anything else, low rpm is much louder. After that, the engine noise muffles the sound. But its present at all times.
Car seems to run fine, and boost seems to build up properly. Unless a clamp got loose, or there's a major boost leak by the discharge pipe/muffler area.
Ill check this over the weekend, and see what I can find.

[JonasJSchreiber]

I had this happen recently on my WRX, because I've had it tuned to boost about 17PSI for the last 60k miles (stock is 14.7PSI). Actually, I'm not sure if that's the reason - but the problem was a bad turbo. Subaru replaced it under warranty thankfully.

EDIT: listening to it, yours isn't nearly as bad as mine was. Mine, you got to 2800RPM and floored it in second or third, and you'd hear a literal whistling until redline. This experience makes me loathe to run tunes for extended periods anymore. I won't be doing the same in my S3.

[selp]

To all,
I removed the discharge pipe, and check the compressor side of the turbo.. didnt see any oil crude oil, more like a cooked oil, which is what I expect to see. Nothing dripping and nothing excessive. I checked the intercooler side (hot side) and found no oil either.
I checked the shaft play on the compressor side of the turbo, and there is little to no play ( from previous experiences, I think this is normal ). I removed the downpipe side of the turbine and also felt a little shaft play, but it didnt seem too excessive. knowing that we have a journal bearing turbo, there is supposed to be some side to side play in order for the layer of oil to form, but it is my understanding that there is not supposed to be any shaft play in and out.

Anything else I can check? turbo seems fine.. unless there is something I am missing completely.

[jpy1980]

After taking it apart and putting it back together, did that help with the noise?

[rohulla]

I was having a similar sound like that and my turbo went out, luckily the warranty covered it.

[HurrayFive]

To all,
I removed the discharge pipe, and check the compressor side of the turbo.. didnt see any oil crude oil, more like a cooked oil, which is what I expect to see. Nothing dripping and nothing excessive. I checked the intercooler side (hot side) and found no oil either.
I checked the shaft play on the compressor side of the turbo, and there is little to no play ( from previous experiences, I think this is normal ). I removed the downpipe side of the turbine and also felt a little shaft play, but it didnt seem too excessive. knowing that we have a journal bearing turbo, there is supposed to be some side to side play in order for the layer of oil to form, but it is my understanding that there is not supposed to be any shaft play in and out.

Anything else I can check? turbo seems fine.. unless there is something I am missing completely.

I was traveling for work and totally missed your reply. As mentioned previously, scoping out the housings doesn't always indicate a problem unless it's severe enough to have damaged the fins on the compressor or turbine wheels and scarred the housings, doesn't sound like the case here.

Also, because these IHI turbo's are all journal bearing, they have a play tolerance built in that's impossible to measure accurately without a dial gauge, which is why I mentioned taking it to your shop (because most people don't have a dial gauge laying around the garage). The gauge is propped against the shaft and can measure both radial and axial play, of which there are factory tolerances for both, the most recent IHI specs I could dig up look like the following:

Axial (maximum): .196 mm or .0077"

Radial @ Compressor: .300 mm +/- .02 mm or .0118" +/- .0008"

Radial @ Turbine: .560 +/- .02 mm or .0220" +/- .0008"

This was from an older post and may be inaccurate for the newest generation turbos though. Any tuning shop specializing in VW/Audi (or turbocharging in general) will have a gauge and these numbers handy and probably charge an hour's worth of labor to check and give an opinion on the noise if you don't want to flash back to stock and fuss with the dealer just yet. If I were you I would get this checked to be safe

[selp]

HurrayFive,
Thanks for the response. That makes sense. I guess I will have to take it in to the dealership and see what they say.
Do you know if the new turbos, or the replacement turbos have been revised or made better to avoid issues?

jpy1980,
No. The noise is still there.

I guess its time to remove the exhaust, intake, intercooler pipe and put the software back to stock.

[HurrayFive]

HurrayFive,
Thanks for the response. That makes sense. I guess I will have to take it in to the dealership and see what they say.
Do you know if the new turbos, or the replacement turbos have been revised or made better to avoid issues?

jpy1980,
No. The noise is still there.

I guess its time to remove the exhaust, intake, intercooler pipe and put the software back to stock.

I was following the other forums when the 8V was first released in Europe and in the first year alone they went through 3 or 4 different revisions of the initial turbo on the GTI/A3 & the R/S3, they've gone through a couple more since. One of the lead techs at my tuning shop mentioned they had seen a "higher than normal" number of turbo failures where the compressor shaft actually shears along the axis and that the revisions were corrections to fix it. I think it's luck of the draw regardless, even a "higher than normal" percentage of failure could still be really small compared to total number of turbos in the wild that never have a problem.

Until the dealer or another shop takes a look, no idea if it's actually even your turbo yet anyway, could be something else! If it is, and absolute worst case scenario the dealer doesn't want to cover it...APR's Stage 3 kit has an EFR turbo that's ball bearing and much more stout overall, and their fueling kit adds port fuel injection to help keep your intake valves clean. If mine ever decides to crap out early I'm going that route :)

[16s3pang]

[bakedcorn]

LMAO - love it!

[selp]

HurrayFive,
I got the chance to update the software on the ECU and DSG, but unfortunately the noise is still there.
I was able to point it to the bottom of the car, the turbo doesn't seem to be making that noise at all, i got up and close to it and tried to listen any noise from it, and nothing. Seems to be coming from the bottom of the driver side of the car. While standing still, I rev the engine to about 1.8k rpm, and the noise appears. When the car starts up cold, the noise is loud too, I was able to check and the noise does come from the bottom.
Also, it seems to be throttle dependent, not rpm or boost related. I might be a bit concerned that its DSG related.. have we heard of any issues like that?

[HurrayFive]

HurrayFive,
I got the chance to update the software on the ECU and DSG, but unfortunately the noise is still there.
I was able to point it to the bottom of the car, the turbo doesn't seem to be making that noise at all, i got up and close to it and tried to listen any noise from it, and nothing. Seems to be coming from the bottom of the driver side of the car. While standing still, I rev the engine to about 1.8k rpm, and the noise appears. When the car starts up cold, the noise is loud too, I was able to check and the noise does come from the bottom.
Also, it seems to be throttle dependent, not rpm or boost related. I might be a bit concerned that its DSG related.. have we heard of any issues like that?

That it happens outside of boost and (I'm assuming while in neutral) while revving the engine from a standstill means it's pretty unlikely to be the turbo at least, so that's good! Listening to the video again and based on your description it's possible it's a failing fuel pump (the one in the tank, not the HPFP), it's still going to be working even when revving in neutral and that whine is actually pretty close to what a failing one would sound like (generally one that has aged but yours could just be defective). Any failing accessory belt would be accompanied with squealing at cold start, and a failing pulley on an alternator or the like would be accompanied by dimming/flickering lights & gauges in the cabin and is unlikely to have an audible noise.

There is a TSB on our HPFP, they have been known to stick open and leak, but I'm not aware of anything on the LPFP...definitely sounds like that could be the culprit based on your symptoms though, maybe just a bad one from the factory. I don't know how friendly your dealer is, mine doesn't care about the parts, I just flash back to stock on both the engine and trans before I go in. You'll have about 3 engine cycles or 20 miles before a CEL comes on from your DP...my dealer is down the street from my tuning shop so I flash to stock and go straight there so they can work on it before the CEL hits. Even tuned they should replace a faulty fuel pump under warranty, but always a gamble, no guarantees for sure.

[selp]

HurrayFive,
I sent you a private message. But Audizine website is not registering that it got sent out, or I cant find it in the sent folder. Let me know if you do or dont. I would like to talk to you about the dealership in Phoenix, and what they can do to help me. The dealership here is trying to tell me they cant do any work unless the car is back to stock.

[HurrayFive]

HurrayFive,
I sent you a private message. But Audizine website is not registering that it got sent out, or I cant find it in the sent folder. Let me know if you do or dont. I would like to talk to you about the dealership in Phoenix, and what they can do to help me. The dealership here is trying to tell me they cant do any work unless the car is back to stock.

PM sent.

[INYAUDI]

Is the shaft nut suppose to look broken like this? Fins are fine. Slight oil where inlet clamps on. Turbo 06K 145 702 T aka the ones that fail.. Turbo builds boost fine. No issues other than supercharger whine in 1st and slightly in 2nd.